NBSIR 85-3023

Reference

NBS

PUBLICATIONS AlllDb D317MD

CRYOGENIC PROPELLANT SCAVENGING

FINAL REPORT

August 1982 - March 1985

Prepared by

CHEMICAL ENGINEERING SCIENCE —QC ON

100 M BUREAU OF STANDARDS

. U56 R, COLORADO 80303

85-3023

1985

Prepared for

NATIONAL AERONAUTICS AND SPACE

ADMINISTRATION

SPACE SHUTTLE PROJECT

LYNDON B. JOHNSON SPACE CENTER

HOUSTON, TEXAS 77058

NATIONAL BUREAU OF STANDARDS

LIBRARY./

CRYOGENIC PROPELLANT SCAVENGING

FINAL REPORT FOR THE PERIOD

AUGUST 1,1982 -MARCH 31,1985

Prepared by

Chemical Engineering Science Division

National Bureau of Standards

Boulder, Colorado 80303

NBSIR 85-3023

B. Louie

N. J. Kemp

D. E. Daney

Contract No. (T6077J)

Prepared for

National Aeronautics and Space Administration

Space Shuttle Project

Lyndon B. Johnson Space Center

Houston, Texas 77058

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

CONTENTS

Page

ABSTRACT 1

1. INTRODUCTION 2

2. PROGRAM DEVELOPMENT 4

3. PROGRAM DESCRIPTION 11

4. RESULTS AND DISCUSSION 38

5. SUMMARY 51

APPENDICES

A. Derivation of single-phase receiver tank equations 53

B. Derivation of two-phase receiver tank equations 56

C. Tank material physical data 59

D. Conversion factor calculation 61

E. Derivation of supply tank equations 62

F. Plotting routines 66

G. Program listings and sample plots 70

NOMENCLATURE 114

REFERENCES 116

- i i i -

FIGURES

Page

Figure 1. Flow schematic for cryogenic propellant scavenging 4

Figure 2. Flow schematic for the receiver tank 6

Figure 3. Components of the computer model 11

Figure 4a. Effect of varying the heat leak to the ET, LOX (default:

0 Btu/hr (OW)) 40

Figure 4b. Effect of varying the heat leak to the ET, LFL (default:

90,000 Btu/hr (2.6xl04 W)) 40

Figure 5a. Effect of varying the heat leak to the transfer piping, LOX

(default: 104,400 Btu/hr (3.0xl04 W)) 41

Figure 5b. Effect of varying the heat leak to the transfer piping, LFL

(default: 50,400 Btu/hr (1.5xl04 W)) 41

Figure 6. Pressure history of LOX transfer for a heat leak of 2xl0 6 Btu/hr

(5.8x10 s W) to the transfer piping 43

Figure 7a. Effect of varying the heat leak to the receiver tank, LOX

(default: 0 Btu/hr (0 W)) 45

Figure 7b. Effect of varying the heat leak to the receiver tank, LFL

(default: 0 Btu/hr (0 W)) 45

Figure 8a. Effect of varying the initial receiver tank temperature, LOX

(default: 60°F (288.6 K)) 46

Figure 8b. Effect of varying the initial receiver tank temperature, LFL

(default: -290°F (94.1 K)) . . 46

Figure 9. Pressure history of LOX transfer for an initial receiver tank

temperature of 200 °F (366.3 K) 47

Figure 10a. Effect of varying the pump or transfer line sizes, LOX

(default: 4 HP (2982.8 W) , 4 in (10.2 cm)) 49

Figure 10b. Effect of varying the pump or transfer line sizes, LH 9 (default: 0HP (OW), 5 in (12.7 cm)) 7 49

-v-
TABLES

Page

Table 1. System Parameter Descriptions and Initialization Values 13

Table 2. Description of Parameters in the COMMON Statements 14

Table 3. Calculated Constants for Equivalent Length 15

Table 4. Variables Used to Plot System Parameters 20

Table 5. Tank Wall Heat Capacity Constants 30

Table 6. Sample Output for Hydrogen 36

Table 7. Final Conditions Using Default Values 39

-vi -
Cryogenic Propellant Scavenging

Final Report

August 1982 - March 1985

B. Louie, N. J. Kemp, and D. E. Daney

Chemical Engineering Science Division

National Bureau of Standards

Boulder, Colorado 80303

This report is a detailed description of a computer model that has been

developed for assessing the feasibility of low g cryogen propellant scavenging

from the Space Shuttle External Tank (ET). Either pump-assisted or pressureinduced propellant transfer may be selected. The receiver tank is chilled by

emitting a low flowrate of single-phase cryogen through small nozzles. When

two phases are present the flowrate is increased to represent transfer through

the main piping. The program will accept a wide range of input variables,

including the fuel to be transferred (LOX or LH 2 ), heat leaks, tank

temperatures, and piping and equipment specifications.

The model has been parametrically analyzed to determine initial design

specification for the system. Pressure- i nduced transfer of LH 2 can be

accomplished in approximately 7 minutes with a 3-inch (0.076 m) line size.

Pump-assisted scavenging of LOX can be completed in less than 4 minutes by

using a 2 HP (1491.4 W) pump and a 3-inch (0.076 m) line. To maximize the

quantity of LH 2 recovered, the receiver tank should be prechilled to -290 °F

(94.1 K). It was determined that the LOX receiver tank does not require

prechilling and can have a temperature as warm as 300 °F (421.9 K) without

significant venting of fluid.

Key words: computer model; cryogenic; fluid transfer; low-g; scavenging;

thermodynamics.

1
1. INTRODUCTION

The continuing success of the frequent Space Shuttle flights has encouraged interest in suborbital scavenging of propellants. Currently, the surplus

liquid hydrogen (LH^) and oxygen (LOX) are jettisoned with the external tank

(ET) or vented to space after the main-engine cutoff (MECO). Nearly 10,000

pounds* (4535.9 kg) of fuel remain after MECO, which can be compared to the

full payload of 65,000 pounds (29483.4 kg). Significant savings can be

realized immediately with the proposed scavenging. Accomplishment of this

task would support the longer range concepts of tethered vessel storage or

orbiting space station operations.

Brux and Stefan [1] have studied the physical phenomenon of cryogenic

propellant transfer and discuss the logistics of the task, including receiver

tank configuration and location, various heat fluxes, and the duration of a

mated coast period after MECO required to meet settling thrust requirements

for the ET. They find the concept feasible, provided a positive acceleration

-4

of 1 x 10 g's or greater is continued for a period of five to twenty

minutes. A period of twenty minutes is required for the worst-case transfer

of both fluids. The transfer of liquid oxygen requires a 2 to 7.5-inch (5 to

19 cm) line size and a boost pump. Liquid hydrogen transfer can be

accomplished using a 4-inch (10 cm) line size with no pump. Simulation of the

transfer incorporates a receiver tank cooldown period, during which a low

flowrate of cryogen is circulated.

*This report does not conform with NBS policy on SI units. At the request of

the sponsoring agency, NASA-JSC, English units are used for the input and

output of data.

2
The present investigation was undertaken to determine the possibility of

propellant scavenging and to evaluate the conditions required for successful

ET residual transfer. A computer model written in FORTRAN IV (FORTRAN 66) is

based on a thorough thermodynamic analysis of the shuttle receiver vessel,

including cooldown of the vessel interior, and heat fluxes to the ET and

shuttle tank. The model is analyzed parametrical ly in order to provide

information to be used in the design of such a system.

This report summarizes our development of a computer model for cryogenic

propellant transfer at the National Bureau of Standards. Fundamental

equations, system description, and assumptions are presented in section 2

entitled PROGRAM DEVELOPMENT. Program logic and descriptions of parameters,

subprograms, and numerical methods are discussed in section 3 entitled PROGRAM

DESCRIPTION. The effect on the overall time of transfer and other operational

characteristics is analyzed using parametric variations. Factors that are

considered include heat leaks, vessel prechilling, and cooldown requi rements.

These topics are discussed in section 4 entitled RESULTS AND DISCUSSION.

3
2. PROGRAM DEVELOPMENT

The physical situation described by the computer model is the transfer of

cryogenic propellant between two tanks in a low-gravity environment. A simplified schematic of the propellant scavenging system is shown in Figure 1. The

points labeled 1 and 2 respectively denote the main fill line into and vent

line from the receiver tank.

R.V.

Figure 1. Flow schematic for cryogenic propellant scavenging

4
The process begins with a cooldown of the receiver tank by spraying the tank

walls with cryogen. This is accomplished by emitting a low flowrate of

cryogen through tangential spray nozzles while the main fill line is closed.

Following the cooldown period the cryogen is transferred through the main fill

line by utilizing ullage pressure in the supply tank or by pumping. The

transfer is complete when the receiver tank is full, when the supply tank is

empty, or when the back pressure in the receiver tank becomes too large.

The model is developed from the differential mass and energy balances

applied to the receiver and external (ET) tanks. There are two separate

thermodynamic conditions which must be considered for the receiver tank.

During the cooldown period, there is only vapor in the tank. Following this

single-phase process, a two-phase transfer into the tank by the cryogen must

be described. Allowances for pressure relief are made to cover those

instances where the tank pressure becomes too great and venting of the vapor

to space results. The receiver tank derivation is based on the following

assumptions:

(1) Heat leaks into receiver and supply tanks (dQ and dQ

s

) are independent of tank temperature and pressure.

(2) The enthalpy of the vented fluid (h^) is equal to the receiver tank

vapor enthalpy (h

v

).

(3) Receiver tank vent pressure is independent of tank temperature.

(4) There is sufficient settling so that only liquid is drained from the

supply tank, and only vapor is vented from the receiver tank.

A complete derivation of the single-phase receiver tank equations is

given in Appendix A. Although the equations are derived for a differential

mass, dm, they are equally valid when dm is considered a flowrate. Figure 2

5
shows the thermodynamic properties for the receiver tank associated with the

fluid in the inlet, vent and tank. The equations are summarized as follows

(definitions for the equation variables are found in the table of

nomenclature):

Mass balance -

dm

1 dm„

dP = -T + ~T

Energy balance -

( 1 )

dU = dQ + h^dm-^ + h^dn^ ( 2 )

Inlet

dm1 hi

u i dQ-j

B

Receiver Tank

i<k 24l

dm dmy, dm,

h h v , h, u Uy, u,

P P^Pt

P, dQ

a

Venting

dm2

h2

u 2

dQ2

Figure 2. Flow schematic for the receiver tank

6
Differential temperature equation -

(J)Tdm + —

£

(h

1

- h)

dT =

dm. + £2

V

pV

m C w w

Differential pressure equation -

for P < vent pressure:

dP =

<|>[0dm + (h n - h)dm + dQ - m C dT]

X w w

dm = dm^ and dm

2 = 0

for P > vent pressure:

dP = 0

dm =

(h - h

1

)dm

1

- dQ + mw

Cw

dT]

dm

2 = dm - dm^

( 3 )

(4)

(5)

( 6 )

A complete derivation of the two-phase receiver tank equations is given

in Appendix B. These equations are summarized as follows:

Mass balance -

dm^ + dm

2 = dmv + dm^ (7)

Energy balance -

dU = dQ + h-^dm^ + h^dir^ (8)

7
Constant volume -

V = \) n + v m £ £ v v

( 9 )

0 = v n dm„ + m^dv, + v dm + m d\>. £ £ £ £ v v v

The density, or p , is substituted for the specific volume. Solving for

the change in the mass of the liquid yields the following equation:

dm

fi =

P—£

(dm + dm ) - p m av— + m 3y dP

p 1 2 £ £ ap . v F ap

v £ vj ( 10 )

If the pressure is less than the vent pressure, the change in the pressure is

given by:

dP =

h.. - u + — (u - h,

)

1 v P v £ 1

dm

1 + (dQ) (l - ^

where

F(P)

F(P) = m. 9u

55,^

1 ‘^ + p*vH (uv- y

av

+ m ijv V

1 ’ pJ)

+ pv(If)v (Uv ' v

(lla)

(lib)

- mw

Cw l i)sat 1 1

and dm^ = 0.

8
If the pressure is the same as or exceeds the vent pressure, the tank

pressure is constant. The differential pressure and mass flow through

the vent are as follows:

The ET model is based on the assumption of non-equilibrium (thermal

stratification) between the liquid and vapor phases remaining in the supply

tank. This assumption is valid because the prechilled supply tanks contain

subcooled liquids and the nominal amounts of fuel remaining after MECO are

extremely small. Thus, no significant mass transfer can take place between

the phases unless the temperature increases enough to vaporize the liquid.

When this occurs, the transfer of fuel stops since severe pump cavitation

conditions are present.

The following set of equations describes the supply tank at any time:

Energy balance -

dP = 0

dm'2 ( 12 )

dQ- + v dP

v vapor phase: dhv m. (13a)

v

liquid phase: dh^ = -— + v^dP (13b)

Pressure equation -

drn^ + VQy +

( 14 )

9
Temperature equation -

+ VidP

Derivations of the above equations can be found in Appendix E.

( 15 )

Once the supply tank liquid enthalpy is determined, the enthalpy of the

fluid entering the receiver tank can be calculated by:

h - h

dQ

! w

1 s dm^ dm

^

and

dh = dQ

s xs

( 16 )

10
3. PROGRAM DESCRIPTION

3. 1 Overview of the Computer Model

Figure 3 shows the components of the computer simulation program and the

communication paths as indicated by the direction of the arrows.

Figure 3. Components of the computer model

The program is written in FORTRAN IV and uses program subsections called

subroutines and functions. The four major program sections are the main

program SCAVAG and the subroutines COOL, SUPPLY and PFAIL. SCAVAG performs

three distinct operations in modeling the scavenging of cryogenic propellant:

11
1) it serves to initialize the system parameters and direct the program flow;

2) it transfers the calculations of the single-phase receiver tank and the

external tank to subroutines; and 3) it performs the calculations of the

two-phase receiver tank. COOL and SUPPLY perform the thermodynamic

state calculations of the single-phase receiver tank and external tank,

respectively. PFAIL sets up plotting arrays and prints messages signifying

which completion procedure is chosen in the program.

Provision is made at the start of the main program to select the propellant for the simulation. The namelist option is used to select the

propellant. The program default value is NGAS=1, which signifies that LH2 has

been chosen. By using the namelist FUEL and setting NGAS=2, LOX can be

selected.

The default values for the parameters for the entire system are initialized according to the propellant chosen. Many of these values are the same as

those used by Brux and Stefan [1]. The parameters and their default values

are given in Table 1. A namelist option called NAME is used to change any of

the initialized values.

COMMON statements are used to pass the same value for a parameter between

different portions of the program. For instance, the calculations in the main

program and subroutines are dependent on the elapsed time or the quantity of

propellant. Table 2 gives a general description of the parameters associated

with each of the COMMON statements.

Propellant selection is important in determining the correct fluid

thermodynamic properties. The properties data are part of the Fluids Pack

computer programs [2] which use routines based on real fluid properties for

oxygen and parahydrogen to calculate various thermodynamic properties [3, 4,

5]. The thermodynamic properties, such as saturation pressure, density,

12
Table 1. System Parameter Descriptions and Initialization Values*

Parameter Value

Location Name Description LOX lh 2

Supply PET Pressure 20 (0.138) 32 (0.221)

Tank TET Temperature -315 (80.2) -425 (19.1)

QET Heat leak 0 (0) 90000 (26376.3)

VET Volume 19786 (560260.4) 53518 (1515415.7)

TOTAL Mass of propel lant

to be transferred

6270 (2844.0) 3098 (1405.2)

Receiver PRESS Pressure 1 (0.007) 18 (0.124)

Tank TEMP Temperature 60 (288.6) -290 (94.1)

Q Heat leak 0 (0) 0 (0)

VOL Vol ume 300 (8494.8) 780 (22086.5)

MWALL Mass of tank wal

1

350 (158.8) 975 (442.4)

PVENT Vent pressure 30 (0.207) 30 (0.207)

Transfer DIAM Pipe diameter 4 (10.16) 5 (12.70)

Pi pi ng LENGTH Length of straight pipe 100 (30.48) 70 (21.34)

NELB0W Number of elbow fittings 20 10

NGATE Number of gate valves 0 0

NGL0BE Number of globe valves 2 2

NANGLE Number of angle valves 1 0

NBUTT Number of butterly valves 0 0

METER Number of flow meters 1 1

QPIPE Heat leak 104400 (30596.5) 50400 (14770.7)

POWER Pump power 4 (2982.8) 0 (0)

Cooldown CDLENG Length of straight pipe 20 (6.10) 20 (6.10)

Pi pi ng NN0Z Number of nozzles 6 6

NOZDIA Nozzle diameter 0.25 (6.4xl0- 3

) 0.500 (1.3xl0- 2

) HEADIA Header diameter 1.000 (2. 5xl0- 2

) 2.000 (5.1xl0- 2

) CONST 1. /orifice constant 1.639 1.639

*Units used to initialize parameters: pressure - psia (MPa),

°F (K), heat leak - Btu/hr (W), volume - cubic feet (liters)

(kg), power - horsepower (W), length - feet (m), diameter -

temperature -

, mass - pounds

inches (cm).

13
and thermal conductivity, are found by using subroutines and functions built

into Fluids Pack. When LOX or LH 2 is chosen, the subroutines DATA 02 or DATA

PH2 are called.

The distinction between propellants is considered at other points in the

computer code. The plotting and numerical integration routines are dependent

on the propellant chosen. PFAIL writes the propellant name into a data file

which is used in producing the output plots. The time step in each numerical

integration is based on the values of the flowrate into the receiver tank and

which propellant is used. Also, since the receiver tank construction

materials are different for LOX and LH 2 , the heat capacity calculation for the

tank wall in FUNCTION CWALL requires this distinction.

Table 2. Description of Parameters in the COMMON Statements

Name Description of parameters

PARAM initialized, constant values

SUB time dependent

FLOW time dependent and transfer piping

NOZZLE cool-down piping

PUMP pump values

NGAS choice of propellant

ETANK supply tank

PROB programmed exit designation

After the parameters have been initialized, they are converted to SI units.

This is done to ensure compatibility with the thermodynamic data required from

the Fluids Pack routines. All subsequent calculations are performed in SI

units, with the exception of those in the plotting routine.

14
Before the transfer of fluid begins, the equivalent length of pipe between

the supply and receiver tanks is calculated. Data for equivalent lengths of

various pipe fittings are taken from Bennett and Meyers [6]. The equivalent

length of each fitting is linearly proportional to the pipe diameter as given by

D + C II (17)

The constants are shown in Table 3. The total equivalent length is calculated

by summing all the individual equivalent lengths. The equivalent length is

then used by FUNCTION FLO and FUNCTION PUMPFLO to calculate a flowrate between

supply and receiver tanks.

Table 3. Calculated Constants for Equivalent Length

c

i c n

90° elbow 2.53 0.414

Gate valve 0.571 -0.0125

Globe valve 38.1 0.107

Angle valve 14.2 -1.18

Butterfly valve 1.79 -0.147

After parameter initialization and unit conversion has been accomplished,

the thermodynamic condition of the supply tank is established. This procedure

involves determining the quantity of ullage vapor in the tank. The initial

flowrate between the tanks is calculated using the pressure difference between

the tanks and the pressure drop through the piping with FUNCTION FLO. If the

flow is aided by a pump, the increased flowrate as calculated in FUNCTION

PUMPFLO is used.

15
3. 2 Description of Program Sections

SCAVAG

The main program SCAVAG directs the sequence of calculations in the simulation. Following parameter initialization and unit conversion, the cool-down

of the receiver tank takes place by calling SUBROUTINE COOL. When the receiver

tank is cooled, there are two phases present and a return is made to SCAVAG.

It is assumed that the transfer piping is simultaneously chilled.

The remaining propellant is transferred in two phases. First, the

enthalpy of the fluid entering the receiver tank is computed by using an

energy balance on the transfer piping. The density and enthalpy of the liquid

and vapor are found with Fluids Pack functions. These values are used in the

first law of thermodynamics to find the internal energy of both phases in the

receiver tank. Next, the integration of the differential pressure and mass

equations, Eq. ( 10 ) - ( 12 ) , is carried out over an incremental time step

(forward Euler method) and incorporates the thermodynamic values above. A

check is made to see if the pressure in the receiver tank exceeds the vent

pressure; the mass of propellant in the tank is adjusted accordingly.

Following this, the supply tank properties are updated by calling SUBROUTINE

SUPPLY. Finally, the values for the pressure, flowrate, and propellant vapor

and liquid quantities are stored in arrays for plotting.

This calculation procedure is repeated within a loop until the receiver

tank is full, until all the propellant has been transferred, or until another

condition has been encountered which causes the program to be terminated. For

instance, should the pressure in the tank exceed that of the entering stream,

the transfer stops. If the simulation proceeds normally, SCAVAG calls

SUBROUTINE PFAIL to prepare the data for graphic display.

16
SUBROUTINE COOL

The single-phase cool-down of the receiver tank is performed by SUBROUTINE

COOL until the receiver is at the correct pressure and temperature for a twophase propellant. Contained in the call and subroutine statements are three

parameters that are needed to transfer into and return from COOL. SCAVAG

provides values for the mass of vapor in the tank and the mass of vented vapor.

COOL returns to SCAVAG the differential pressure and the current values of the

mass of vapor in the tank and the quantity vented. A calculation procedure

similar to that in SCAVAG is followed to solve Eq.(l)-(6).

Several thermodynamic quantities are needed to solve the single-phase

differential equations. COOL calls SUBROUTINE PPHI which calculates the

Gruneisen parameter for the single-phase (vapor) propellant in the receiver

tank. A heat balance analysis on the transfer pipe affords the enthalpy for the

entering stream. The Fluids Pack functions are used to find the density,

enthalpy, and specific heat of the fluid in the receiver tank. When all of

these thermodynamic values are known, the equations are solved incrementally,

with the appropriate checks for venting and back pressure. If all the propellant

has been transferred before any liquid is present in the receiver tank, a call

is made to PFAIL to prepare the plotting data and terminate the program. Again,

the supply tank fluid properties are updated by calling SUPPLY.

To determine when two phases are present in the receiver tank, saturation

and actual gas densities are compared. If the gas saturation density at the

receiver tank pressure is greater than the actual tank density, the receiver

tank is two-phase. SUBROUTINE COOL returns to the main program following this

determi nation.

17
SUBROUTINE SUPPLY

When updated supply tank conditions are required in either the main program or SUBROUTINE COOL, SUBROUTINE SUPPLY is accessed to perform the necessary

thermodynamic calculations. The fraction of the supply tank occupied by either

phase is determined first so that the heat flux to the tank can be proportioned accordingly. The vapor phase is assumed to be at the tank pressure and

slightly above the saturation temperature, thereby ensuring that condensation

will not occur. Next, the Fluids Pack routines are called upon to provide

thermodynamic values for the vapor and liquid phases. The Gruneisen parameter

and heat of expulsion for both phases are calculated by using SUBROUTINE PPHI

and FUNCTION TH, respectively. Finally, the incremental changes in the tank

pressure and liquid temperature and enthalpy are found by using Equations

(14), (15) and (13b) and the appropriate time step.

SUBROUTINE PFAIL

SUBROUTINE PFAIL, with ENTRY FULL and ENTRY DONE, terminates the program

and sets up the data and parameters to be plotted. The different entry points

are accessed by unique call statements. PFAIL is called when: 1) the flow

between tanks has stopped due to back pressure from the receiver tank; 2) when

receiver and supply tank pressures are equal and a pump is not used; or 3)

when there is excessive pressure in the receiver tank and a pump is used.

PFAIL writes a message indicating why the simulation stopped and what the

final conditions are. The other entries into PFAIL address other conditions

and bypass inappropriate operations. ENTRY FULL is called when the main program or SUBROUTINE COOL determines that the receiver tank is full of propel18
lant. When all the fluid has been emptied out of the supply tank, ENTRY DONE

is called. ENTRY PDATA is called when a programmed exit has been executed.

Each entry into the subroutine follows a similar computational procedure.

Initially, the units for the parameters to be printed in the termination message are converted to English from SI. Following this conversion, the message

is printed on the output file stating the cause for program termination, the

quantity of propellant transferred, and the temperature and pressure for each

tank. The quantity of fluid vented from the tank is also given.

Preparation of the data and parameters for plotting involves several

steps. The upper and lower limits for the plots are determined first. The

descriptions for the plotting parameters are shown in Table 4. Since each of

the plots depicts a parameter as a function of time, the lower value is set to

zero and the upper value is either 10 or a multiple of 50 minutes. Should the

total time required for transfer be more than 10 minutes, the greater value

will be used.

The lower limit for the receiver tank temperature is based on the initial

temperature in the supply tank, and the upper limit depends on the initial

receiver tank temperature. Both values are multiples of 100 and in units of

Fahrenheit.

The limits on the receiver tank pressure are zero and 50 psia (0.345

MPa), unless a value in the pressure array exceeds the upper limit. When this

is the case, the value is incremented by 50 psia (0.345 MPa) iteratively until

the maximum pressure data point is less than the newly set limit. The upper

limit for the transfer flowrate is 2000 lb/min (907.2 kg/min) for LH 2 or

10,000 lb/min (4535.9 kg/min) for L0X.

19
Table 4. Variables Used to Plot System Parameters

Simulation variable Uni ts Array

Location of low,

high bounds

TIME Mi nutes X 0PL0T(1) , 0PL0T(2)

TEMP °F Y1 0PL0T(3) , 0PL0T (4)

PRESS psi a Y2 0PL0T(5) , 0PL0T(6)

FL0W1 Pounds/mi

n

Y3 0PL0T(7) , 0PL0T (8)

MVAP Pounds Y4 0PL0T(9) , 0PL0T(10)

MLIQ Pounds Y5 0PL0T(11) , 0PL0T(12)

TOTAL Pounds Y6 0PL0T(13) , 0PL0T(14)

ETQ Dimensionless Y7 0PL0T(15) , 0PL0T(16)

TANK Dimensi onl ess Y8 0PL0T(17) , 0PL0T(18)

The quantity of propellant in the receiver tank is graphically displayed

by plotting the vapor, liquid, and combined amounts over time. All these

limits are dependent on the initial quantity of propellant (TOTAL) to be transferred. The upper limit for the vapor quantity is initially set to 500 lbs

(226.8 kg), but it is increased iteratively by 500 lbs (226.8 kg) if one-tenth

of TOTAL is larger than the limit. The upper limits for the liquid and

combined quantities are 10 times the value determined for the vapor quantity.

The quality of the propellant in the supply tank and entering the receiver

tank is stored in the array as percent vapor. The upper limit for the quality

is 100% vapor and the lower limit is 100 percent liquid.

3. 3 Descriptions of Other Subroutines

SUBROUTINE PPHI

The thermodynamic quantity called the GrLineisen parameter, <J>, appears

frequently in single-phase flow [7]. It is found in the equations describing

the single-phase cooldown of the receiver tank (Eq. (3)-(4)) and the subcooled

20
liquid propellant in the supply tank (Eq. (14)) in the present study. Both

subroutines COOL and SUPPLY call PPHI during their computational procedures

for values of <J>.

The dimensionless Gruneisen parameter is given by

or

(18)

(19)

When the second form of 0 is used, the Fluids Pack subroutine DPDT can be used

to find the partial derivative and the constant volume specific heat of the

fluid. The density and temperature are passed from either COOL or SUPPLY to

PPHI which returns a value for <J).

SUBROUTINE CHECK

Calls to this subroutine are routinely made to determine the quality of

propellant. Both SCAVAG and COOL call CHECK to find the quality of the fluid

entering the receiver tank. SCAVAG, COOL, and SUPPLY utilize CHECK to find

the amount of vapor in the supply tank fluid. Because pump cavitation can be

severe with a small quantity of vapor, the run will be terminated with this

determination. A message is printed which states the percentage of vapor in

the fluid.

For inputs of pressure, temperature and enthalpy, SUBROUTINE CHECK determines if the fluid is single-phase or two-phase and the mole fraction in each

phase. First, the liquid saturation enthalpy is obtained from Fluids Pack

using the input pressure. Next, if the input enthalpy is less than liquid

saturation enthalpy, the stream is subcooled, and CHECK returns an indication

21
that no vapor is present (i.e. x -- 0). If the input enthalpy is greater than

the liquid saturation enthalpy, the proportion of fuel in the liquid and vapor

phases is determined by:

h = h 2,sat (1' x) h . (x) v,sat

or rearranging,

x ^£,sat h)/(h^^sat h v,sat^ ( 20 )

Since the flow equations were developed for an incompressible fluid,

there may be significant error if the fraction of vapor is much greater than

zero.

3.4 Descriptions of Functions

Several thermodynamic quantities in the form of partial derivatives are

required in the two-phase calculations in SCAVAG. While Fluids Pack directly

calculates some partial derivatives such as DPDT (which is used in determining

<])), other partial derivatives must be calculated using an iterative approximation. The approximation is written so that thermodynamic properties from

Fluids Pack may be utilized.

FUNCTIONS DVDPV and DVDPL

FUNCTION DVDPV and FUNCTION DVDPL calculate the partial derivative of

specific volume with respect to pressure for saturated vapor and liquid respectively. The pressure is the required parameter in the function statement.

22
These partial derivatives are required by Eq. (10) for the two-phase integration. The partial derivative is approximated by the equation:

/§»\ u sat

(P + AP) ~ ') sat

(P ' AP)

( . u Ws «t

' 2AP

The values for the specific volume at saturation conditions are the inverse of

the density computed by Fluids Pack at the same temperature and pressure. The

pressure increment AP is initially set at 0.05 atm (0.005 MPa) and decreased

until the partial derivative changes insignificantly.

FUNCTIONS DUDPV and DUDPL

FUNCTION DUDPV and FUNCTION DUDPL, given the pressure as an input, determine the partial derivative of internal energy with respect to pressure for

saturated vapor and liquid, respectively, as required by Equation (lib). The

partial derivative is approximated in a similar manner to DVDPV and DVDPL by:

§u\

BP

'sat

u sat(P + AP) “ u sat(P ' AP)

2AP ( 22 )

The internal energy, u is calculated using enthalpy values from Fluids

Pack at the saturation temperature and pressure and the (First Law) energy

relationship as given by:

u = h - (Pv)

or (23)

u = h - (P/p)

Again, AP is initially 0.05 atm (0.005 MPa) and decreased until the desired

accuracy is obtained.

23
FUNCTION DTDP

This function determines the partial derivative of temperature with

respect to pressure for the saturated fluid (liquid and vapor). The partial

derivative is approximated by the expression

Pressure is required as an input for the function and is subsequently used in

the Fluids Pack function FINDTV to obtain the saturated temperature. The

temperature is found at a pressure that is a small increment above and below

the input. The increment, AP, is decreased from an initial value of 0.05 atm

(0.005 MPa) until the convergence criterium is met.

FUNCTION ALPHAL

The temperature equation in SUPPLY contains the term for the liquid phase

bulk expansivity, a^, which is defined as (7):

FUNCTION ALPHAL calculates this value by approximating the partial derivative

in an iterative manner. This approximation is given by:

A temperature increment AT is used to find values of the density at temperatures slightly above or below the liquid temperature. The temperature increment AT is initially set at 0.05 K and decreased until the partial derivative

changes insignificantly from one iteration to the next.

T . (P + AP) - T . (P - AP)

(24)

(25)

(26)

24
FUNCTIONS FLO, FRICT, PUMPFLO, and PEFF

The functions used to calculate the transfer flowrate are dependent on

the pressure in the receiver tank and are themselves interdependent. These

functions are used to calculate the flowrate of propellant between the supply

and receiver tanks. FLO and PUMPFLO are accessed from SCAVAG and COOL. FRICT

is used in FLO and PUMPFLO, and PEFF is used in PUMPFLO only. A description

of each follows.

FUNCTION FLO

FUNCTION FLO calculates the flowrate between tanks for a given pressure

drop. This function is used to initialize the flowrate, and the value it

provides is an input for FUNCTION PUMPFLO. SCAVAG passes the receiver tank

pressure through the function statement.

The flowrate between the tanks is related to the pressure drop in the

system. The overall pressure drop can be stated as the sum of the individual

pressure drops as follows:

AP

system

= AP . (dm2

) mam

+ AP

meter

AP , , (dm2

) cooldown (27)

where (dm2

) is the functional dependence, not the multiplier. The overall

pressure drop is the difference between the pressures in ET and receiver tank.

The pressure drop in the meter is five percent of the overall pressure drop.

The remaining terms in Eq. (27) are functions of the flowrate. The pressure

drop through the main transfer line and the cooldown line are given by:

AP . mai n

32Cf . L . (dm) 2 mam mam v y

p7i 2 D° . K mai n (28)

25
and

AP

cool

32Cf ,L (dm) 2 cool cool

pn 2 D

5cool

(29)

(For the derivation of C, see Appendix D.

)

The pressure drop in the cool down nozzles can be expressed as

AP

nozzle

dm

C

1 D

2 C ,

. o d

(30)

When Eq. (27) is solved for the flowrate dm by substituting into it Eq. (28) -

(30), the following expression is obtained:

dm2 =

P

- P DT - AP . s RT meter

C f + c f + C main main cool cool nozzle

(31)

where C. = C . , C , , or C n refers to the riqht hand side of the

l mai n coo I nozzle 3

individual equations without the flowrate term.

Since the Fanning friction factors in Eq. (28) and (29) also are

functions of the flowrate, an iterative procedure r is used to calculate fmain

and f , . The friction factors are initially set to 0.005 and used to

compute the flowrate. The flowrate is used as the input parameter to FUNCTI0

FRICT, which computes new values for the friction factors. The new values fo

f . and f -i are used to recalculate the flowrate. This continues until main cool

the friction factors change by less than 0.1 percent.

After the receiver tank has been chilled to allow two phases of the

propellant to be present, the nozzle constant, C^, and the length of the cool

down pipinq, L ,, are set to zero. The contribution of the cooldown line

and nozzles to Eq. (27) and (31) is negated. This simulates the switching of

a three-way valve to the closed position in the cooldown line.

26
FUNCTION FRICT

FUNCTION FRICT calculates the Fanning friction factor corresponding to

flow through a pipe. Input variables are the flowrate, temperature, density,

and pipe diameter.

The Fanning friction factor is related to the Reynolds number and pipe

diameter. While a variety of functions are available [8], the following

relationship was chosen:

f = -4 log e/D 5.02

10 \ 3.

7

N Re

loge/D

10 I 3.7

14.5

N dRe

(32)

The pipe roughness s is assumed to be 0.00015 ft (0.004572 cm), the value for

commercial steel pipe [6]. The Reynolds number is calculated from the equation:

N

Re = Du

b p/u

M = 4(dm)M

N Re TiDp (33)

The viscosity as a function of pressure and temperature for hydrogen

cannot be calculated with the Fluids Pack thermophysical properties computer

programs. However, since relatively small changes in hydrogen viscosity do

not significantly change the friction factor, an average viscosity is used.

-4

This value is 1.8 x 10 g/(cm-s) [3] and produces less than 0.5% error in the

friction factor.

27
FUNCTION PUMPFLO

FUNCTION PUMPFLO calculates the flowrate between the ET and receiver tank

and accounts for the use of a pump in the transfer. The overall pressure drop

can be expressed as

AP . = AP, . (dm2

) system line

+ AP . + AP , (dm2

) - AP ( ). (34) meter cool v J pump

v dm J v 1

See the previous discussion in the section on FUNCTION FLO for descriptions of

the terms AP . , AP, . , AP . , and AP , . The term AP is a system’ line’ meter’ cool pump

function of the inverse flowrate, 1/dm, and is given by

AP

pump

bP P n dm (35)

The effect of APp

Ump

is opposite that of the other terms in Eq. (34); hence,

the opposite sign.

An initial guess for the flowrate is used to calculate the theoretical

pressure drop or rise. The flowrate dm is iterated by using a modified Newton

method [9] which is found to be stable for this application:

dm , , = dm - n+1 n

(AP - AP

n )(dmn -dmn

_ 1

)

(AP , v - AP ) n-1 n'

(36)

The iteration ceases when calculated and actual pressure drops differ by less

than 0.01%.

28
FUNCTION PEFF

The pump efficiency is calculated for an input of the flowrate from FUNCTION PUMPFLO. Two different sizes of pumps are used to transfer the LOX and

LH 2 propellant. A linear least squares fit of data for the pump efficiency

versus flowrate [10,11] is used to provide a five-coefficient, fourth order

equation for each pump.

The equation for the pump efficiency for LH 2 is:

H = 0.39213 + 0. 096620(dm) + 2.7793 x 10~ 5 (dm)

2

- 8.1723 x 10' 8

(dm)

3 + 2.5008 x 10‘ n

(dm)

4

.

The equation for the pump efficiency for LOX is:

q = 0.32031 + 0. 48261(dm) - 1.6223 x 10"

3 (dm)

2

+ 3.9836 x 10" 6

(dm)

3 - 4.8853 x 10' 9

(dm)

4

.

FUNCTION TH

SUBROUTINE COOL uses FUNCTION TH to calculate a value for the heat of

expulsion for the vapor phase calculations. This thermodynamic value is defined as:

(37a)

(37b)

0 = v (38a)

(tp)

T

(38b)

P

The Fluids Pack subroutines DPDD and DPPT are used to find the partial derivatives in the numerator and denominator, respectively, and Fluids Pack

functions are used for the specific heat and density.

29
FUNCTION CWALL

FUNCTION CWALL returns the heat capacity of the receiver tank wall at a

particular temperature. It is assumed that the oxygen tank is constructed

using Inconel X-750* and the hydrogen tank is constructed using aluminum. The

heat capaci ty-temperature data for these materials are of the form:

Cw

exp(C

1 + C 2

/T + C

3

/T

2

) 1000 (39)

The constants C^, and C^ were determined by taking heat capacitytemperature data and applying a least-squares technique to the above equation.

These values are shown in Table 5. The data used are found in Appendix C

[12,13].

Table 5. Tank Wall Heat Capacity Constants

Inconel A1 umi num

c

i

6.482 7.293

C 2

-106.3 -121.9

C

3

329.1 347.9

3. 5 Program Termination

SUBROUTINE PFAIL is the normal route for program termination. ENTRY DONE

is used when the supply tank is empty, i.e., when all the propellant has been

*Such identification does not imply recommendation or endorsement by the

National Bureau of Standards.

30
transferred. ENTRY FULL is used when the receiver tank is full. This condition occurs if the receiver tank volume is too small, if the quantity of

propellant is increased with the tank volume remaining the same, or if the

mass balance on the fluid in tank is wrong. The main entry PFAIL is used to

indicate a high backpressure condition. This can happen when the receiver

tank pressure is greater than the supply tank pressure and a pump is not used,

or when the flowrate is very small. The program will terminate if there is

improper venting, i.e., when there is a measured flow through the vent, but

the receiver tank pressure is less than the set vent pressure.

ENTRY PDATA in SUBROUTINE PFAIL is used when a programmed stop is

executed. This exit is used in several locations in the main program and cool

down subroutine, and it is also used by functions DVDPV, DVDPL, DUDPL, DTDP,

ALPHAL, FLO, and PUMPFLO and subroutine SUPPLY. The COMMON parameter DUMP

normally has a value of zero until a cause for termination is reached in one

of the previously listed program sections. DUMP is reset to a value of 1.0.

When the condition for termination occurs in a function, the program flow is

returned to either SCAVAG or COOL. The run continues to the end of the present

integration loop, when the parameter DUMP is evaluated. If DUMP equals 1.0,

ENTRY PDATA is called, and the output files are replaced prior to termination.

Several subprograms use convergence criteria to obtain specific thermodynamic conditions. SUBROUTINE COOL checks for the condition when the density

in the tank is greater than the saturation density, i.e. both liquid and

vapor are present in the tank, and the calculations return to the main

program. If two phases are not obtained within the array size limit, the

program prints an error message and stops.

Functions DVDPV, DVDPL, DUDPV, DUDPL, DTDP, and ALPHAL use derivative

approximations that depend on the change in thermodynamic properties about a

small interval. The first five functions listed above evaluate the specific

31
volume, internal energy, or temperature about a small pressure interval, while

ALPHAL evaluates the density about a small temperature interval. In all

cases, the program will terminate should the convergence of the properties

about the specified interval not be reached within 100 iterations. The

message, "KOUNT exceeds 100," noting the particular function, will be printed.

FUNCTION FLO uses the Fanning friction factor calculated in FUNCTION

FRICT as its convergence criterion. The flowrate found in FLO is an input for

FRICT, which in turn determines the friction factor used in the flowrate

calculation. The convergence of the successive values should occur within 100

iterations, or the message, "KOUNT exceeds 100 for FLO," is printed on program

termination.

FUNCTION PUMPFL0 checks the convergence of the actual pressure difference

between the tanks and the calculated pressure drop through the piping using a

pump. If the convergence between the two does not happen within 100 iterations, a message is printed and the program is stopped.

The supply tank thermodynamics are checked for errors in calculation or

intolerable operating conditions in SUBROUTINE SUPPLY. When the calculated

liquid enthalpy is significantly different from the enthalpy found in Fluids

Pack, the program terminates with the message, "ENTHALPY DISPARITY," and

prints the two values in disagreement. If the quality of the fluid is greater

than one part in one million, there exists the possibility for cavitation.

The program terminates with this condition and an error message, "ET LIQ

BOILING. STOP TRANSFER."

3. 6 Programming Information

A brief description will be given for a typical run of the program. The

information provided in this section is based on procedures used with the CDC

32
Cyber 750 Computer System and the NOS Version 1 operating system on location

at NBS in Boulder. The program is written in FORTRAN IV. These procedures

should be transferable to the computer system at NASA- JSC with minor

modifications. See Appendix G for program listings.

File Manipulation

All computer programs, data, and control procedures for running PROGRAM

SCAVAG are stored in files. At NBS, SCAVAG is stored in filename COMBO; the

input data are stored in filenames DATAIN or FUEL; output data are located in

filenames PSDATA and PSOUT ; and the control procedure is stored in filename

SUBCOM.

Before running PROGRAM SCAVAG, the operator must prepare the control

procedure and the input files. The control procedure that NBS has used,

SUBCOM, retrieves COMBO, DATAIN, and BOXB (containing Fluids Pack) from

permanent storage and places them into a local or usable state. SUBCOM

compiles COMBO and, if the compilation is free of errors, loads and executes

the compiled version.

The operator enters the following command on a time-sharing terminal to

run the program:

SUBMIT, SUBCOM

This statement is a batch command which means the operator cannot interact,

alter, or stop the execution of the program or job. To determine when the

program has stopped, the operator can check the status of the job, or a file

named DAYF. This file is created by SUBCOM to record the real time sequence

of control procedures performed by the computer during program execution.

33
Input

The program operator must determine which propellant and values for the

initialized parameters are to be used. If LOX is the desired propellant, the

namelist FUEL must be modified to the following form:

$FUEL

NGAS=2

,

$

If LH 2 is chosen, FUEL should have either of the following forms:

$FUEL

$ or $FUEL

NGAS=1,

$

Namelist FUEL is contained in a file named FUEL. No decimal point is used

since NGAS is an integer.

To change values for the initialized variables, similar steps are used

with namelist NAME. NAME is contained in a file called DATAIN. Any number of

changes can be made for the parameters listed in Table 1. For instance, to

change the initial supply tank temperature and pressure, the quantity of

propellant to be transferred, the pump power, and the length of straight pipe

for the LH2 system, one would alter NAME to the following form:

$NAME

TET = -400.

,

PET = 25.

,

TOTAL = 5000.

,

POWER = 2. , LENGTH = 100.

,

$

Since all the chosen variables are real, the values must have decimal points.

All values are entered in English units. If no changes are desired, NAME must

have the following form:

$NAME

$

34
The program statement defines TAPE5 and TAPE7 for use during the program.

SUBCOM, which directs the sequence of operating steps for running the program,

sets TAPE5 equal to filename DATAIN, or namelist NAME, and TAPE7 equal to

filename FUEL, or namelist FUEL. These files must exist in order to run the

program.

Output

The output from program SCAVAG is directed to two locations. While SCAVAG

is running, the graphic display data is written to TAPE8 and stored in filename

PSDATA. When SCAVAG terminates, the termination message and initialized parameters are written to TAPE6 and stored in filename PSOUT. See Table 6 for

sample output for LH 2. The operator can access PSOUT at a later point for

further evaluation.

Two FORTRAN programs utilize the data in PSDATA to produce plots describing the transfer. The first program is called PLOT. At NBS PLOT is

attached to the job by the control procedure SUBCOM and run after SCAVAG has

terminated. The plots that are drawn use the computer systems mathematics

library (called STARPAC at NBS in Boulder) and are written to TAPE6, following

the output described above. The entire contents of TAPE6 are stored in PSOUT.

(Further explanation is given in Appendix F.)

The second program which uses PSDATA is called DEMO. The graphics package called DISSPLA (15) is utilized to produce plots which are more refined

than those generated through PLOT. (Additional details about DEMO can be

found in Appendix F.) The plots are directed to one of three output devices

by selecting the appropriate CALL statement in DEMO. For the computer system

at NBS CALL HP7221 accesses a multiple pen plotter; CALL TK4010(960) accesses

35
Table 6. Sample Output for Hydrogen

Supply tank initial conditions:

Pressure

Temperature

Hydrogen Mass

Heat Leak

32.000 psia

-425.000 F 3098.00 Pounds

90000.000 Btu/hr

(0.221 MPa)

(19.1 K)

(1405.2 kg)

(26376.3 W)

Receiver tank initial conditions:

Pressure

Temperature

Vent Pressure

Tank Volume

Tank Wal 1 Mass

Heat Leak

18.000 psia

-290.000 F 30.000 psia

780.000 Cubic Feet

975.000 Pounds

0.000 Btu/hr

(0.124 MPa)

(94.1 K)

(0.207 MPa)

(22086.5 kg)

(442.2 kg)

(0.0 W)

Transfer Parameters:

Pipe Diameter

Length of Straight Pipe

10 Elbow(s)

0 Gate Valve(s)

2 Globe Valve(s)

0 Angle Valve(s)

0 Butterfly Valve(s)

1 Flow Meter (s)

Heat Leak Into Piping

Pump Power

Cool-Down Parameters:

5.000

70.000

Inches

Feet

(12.7 cm)

(21.34 m)

50400.000

0.0

Btu/hr

HP

(14770.7 W)

(0.0 W)

Length of Piping

Number of Nozzles

Nozzle Diameter

Header Diameter

20.000 Feet

6

0.500 Inches

2.000 Inches

(6.10 m)

(1.3xl0- 2 m)

(5. Ixl0- 2 m)

Cool-Down Time 0.1754 minutes

At 2.344 minutes from start of propellant transfer the supply tank is empty.

At this time the, receiver tank is at -422.89 °F (20.3 K), 16.23 psia (0.112

MPa), and contains 3098.00 pounds (1405.2 kg).

During the simulation 0.00 pounds (0.0 kg) were vented.

Supply tank is at -424.9907 °F (19.1 K), 31.55 psia (0.218 MPa).

36
a graphics terminal; CALL FR80(0.0) accesses microfilm. The running of

program DEMO is separate from running SCAVAG and PLOT. Examples of plots from

program DEMO are found in Appendix G.

37
4. RESULTS AND DISCUSSION

The feasibility of low-g propellant transfer is analyzed parametrically

with the computer model. Particular emphasis is placed on the thermodynamic

changes to the system caused by varying the temperature, pressure, or heat

leak at any point. The principal parameter in this investigation is the

overall time of transfer, since the transfer is to take place during a mated

coast period after MECO. Other parameters of interest in the design of such a

system are the pump size and piping requirements.

Nozzles are used during the cooldown of the receiver tank to induce a

flowrate of propellant lower than the flowrate during the main part of the

transfer. The sizes of the associated piping and nozzles, which are simply

small orifices situated around the header, have been parametrically determined

to accomplish a low flowrate without causing an excessive pressure

drop. This specification holds except in those cases where the transition

from the main piping to the cooldown piping is great. (Further explanation is

provided later.) When two phases occur in the tank, the nozzles are shut off;

the transfer via the main line resumes for the remainder of the simulation.

Because the transfer can require a pump, the liquid from the ET must be

subcooled to prevent cavitation. This is most notably the case for LOX which

has insufficient ullage pressure to accomplish a complete pressurized

transfer. Single-phase flow from the supply tank also requires sufficient

thrust to settle the liquid against the outlet port. We assume such a thrust

for the purposes of this modelling effort.

When the program is run with the default parameters, the time required to

complete the transfer of either propellant is relatively short. Transfer of

LOX with a moderately sized booster pump takes 1.94 minutes; pressurized

transfer of LH2 requires 2.34 minutes. If the MECO mated coast period is

38
scheduled to continue to 20 minutes, the scavenging of both cyrogenic

propellants can be completed in less than 12 percent of the alloted time. The final

system conditions are shown in Table 7. Plots of the transfer are found in

Appendix G.

Table 7. Final Conditions Using Default Val ues

0 2 h 2

Time of Transfer, min 1.936 2.344

Receiver Tank

Temperature, °F (K) -312.35 (81.69) -422.89 (20.28)

Pressure, psia (MPa) 6.72 (0.046) 16.23 (0.112)

Mass in Tank, lb (kg) 6270. (2846.6) 3098. (1405.2)

Mass Vented, lb (kg) 0 . 0 .

Supply Tank

Temperature, °F (K) -314.9998 (80.22) -424.9907 (19. 12)

Pressure, psia (MPa) 19.88 (0.137) 31.55 (0.217)

4. 1 Heat Leaks to the System

The conditions in the ET are governed by two opposing influences: outflow

and heat leak. In the absence of heat leak, outflow gives an adiabatic expansion of the vapor and a resulting decay in temperature. In the absence of

outflow, heat leak gives an increase in temperature and pressure. Figures 4

and 5 show the expected results of varying the amount of heat to the ET.

Figure 4 shows that a large rate of heat flow into the LOX ET must be present

for a significant change in the system parameters to occur.

39
Temperature,

*F

Heat Leak to the ET, W

15 30 150 300 1500 » 10 *

Heat Leak to the ET, 6tu/hr

Figure 4a. Effect of varying the heat leak to the ET, LOX (default:

0 Btu/hr (OW))

Heat Leak to the ET, W

1 5 3 15 30 « 10

4

Heat Leak to ET, Btu/hr

Figure 4b. Effect of varying the heat leak to the ET, LH

? (default:

90,000 Btu/hr (2.6xl0 4 W))

^

40
Heat Leak to Transfer Piping, W

10 15 20 25 30 * 10* —1 15 * 10"1

X.

«f3

15&

E _

10

TO Q_2

Sf3

(/)

—1 o

Figure 5a. Effect of varying the heat leak to the transfer piping, LOX

(defualt: 104,400 Btu/hr (3.0xl04 W))

Heat Leak to Transfer Piping, W

0 5 10 15 * 10 ' - 28 * 10

' !

- 24

X. — 20

— 12

— 8

t

16 £

Figure 5b. Effect of varying the heat leak to the transfer piping, LH,

(default: 50,400 Btu/hr (1.5xl04 W))

41
6 5 The value at which this occurs is on the order of 10 Btu/hr (2.9 x 10 W).

The pressures in both tanks undergo rapid increases, while the temperatures

show slight increases.

The changes in temperature and pressure that the LH 2 system experiences

are less abrupt than those of the LOX system. They do show the same trends,

however. As the heat leak to the ET is increased, the pressures and

temperatures show gradual increases.

As the heat leak to the transfer piping is increased, the final

conditions in the receiver tanks for both propellants show a corresponding

rise greater than the results for a heat leak to the ET. The results are

presented in Figure 5. Venting occurs for LOX when the heat input is

6 6 increased to 5 x 10 Btu/hr (1.5 x 10 W); approximately 28% of the propellant

is vented. The LOX temperature of -284.29 °F (97.28 K) at the vent pressure

is located at the liquid-vapor boundary. The pressure history for this

transfer is shown in Figure 6.

Similar observations can be stated for the case of LH2

. When the heat

leak to the transfer piping is increased to 10^ Btu/hr (2.9 x 10^ W), a small

amount of fuel is vented. This occurs at the end of the transfer, as the

fluid reaches the liquid-vapor boundary.

Conditions in the ET do not vary with an increased heat leak to the

piping. This is due to the flow of cryogen from the tank which directs any

potential effects to the receiver tank. The overall time of transfer

increases linearly for both LOX and LH 2

. The time required to transfer LOX

remains quite brief, but the transfer requires an additional minute when

5 x 10^ Btu/hr (1.5 x

10'^ W) leaks into the LH 2 piping.

The effect of heat leak into the receiver tank is similar to that into

the transfer piping. For LH 2 the transfer time is increased by nearly a

5 5 minute for a heat rate of 4 x 10 Btu/hr (1.2 x 10 W). Increasing the heat

42
PRESSURE

(PSIfl)

Fi gure

50.

0

n

10 . 0

-

30.0-

20 . 0

-

10 . 0

-

o.o -r 1 1 1 1 1 1 1 1 1

1 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 1.0 1.5 5.0

TIME (MINUTES)

6. Pressure history of LOX transfer for a heat leak of 2xl0 6 Btu/hr

(5.8x10 s W) to the transfer piping

43
leak to the receiver tank at the rate of 10^ Btu/hr (2.9 x 10^ W) causes LH 2

to vent. The transfer time for LOX rises smoothly with increased heat input;

an additional minute is required to transfer LOX at a heat leak of 1.2 x 10^

5 Btu/hr (3.5 x 10 W). Also, venting takes place at this rate of heat

addition. These results are shown in Figure 7.

4. 2 Receiver Tank Temperature

Since the temperature for the LOX receiver tank is unspecified in the

study by Brux and Stefan [1], the effects of several temperatures were

examined in this study. The results are shown in Figure 8. It can be assumed

that the receiver tank will receive some soakback heat leak from the

insulation as well as radiation prior to MECO. Thus, temperatures higher than

cryogenic are realistic and allow examination of the chilldown process. A

wide range of initial temperatures neither significantly alters the time

required to transfer the oxygen nor the final receiver tank temperature. The

coolest temperature input of -100 °F (199.7 K) would require the vessel to be

prechilled on the ground. For temperatures above 120° F (321.8 K) a small

amount of venting (less than 1 percent) takes place at the beginning of transfer.

This rapid increase of the RT pressure to the vent pressure is shown in Figure

9.

The study by Brux and Stefan [1] recommends that the LH 2 receiver tank be

prechilled to -290 °F (94.1 K) to prevent venting during the transfer after

MECO. They state that at higher temperatures, a large amount of venting would

be required to achieve chilldown of the receiver tank. We find that only

minor venting at the start of the transfer takes place when given an initial

temperature between -250° F (116.3 K) and -50 °F (227.4 K). For all cases,

the overall time of transfer is less than 2.80 minutes.

44
Heat Leak to Receiver Tank, W

0 12 3 4

30* 1 (T

J

cT3

</) 1C £

10

o

Figure 7a. Effect of varying the heat leak to the receiver tank,

(default: 0 Btu/hr (0 W))

Heat Leak to Receiver Tank, W

o 5 10*103

25 * 10‘ ?

20

CL2

tfD

CL

10

LOX

Figure 7b. Effect of varying the heat leak to the receiver tank, LH

(default: 0 Btu/hr (0 W))

45
Initial Receiver Tank Temperature, K

200 300 400

84 —

83

82 - <u

k_3

CO

k_

<DCL 81 E

<D .

- 80

79 —>0

15x10-1

10

Q_

Jfi k_ CL

Figure 8a. Effect of varying the initial receiver tank temperature, LOX

(default: 60°F (288.6 «))

Initial Receiver Tank Temperature, K

100 150 200

20 x 10'2

CO CL

<U 15 ^

10

Figure 8b. Effect of varying the initial receiver tank temperature, LH,

(default: -290°F (94.1 «))

46
PRESSURE

(PSIR)

50.

O

n

40.0-

0.0 1 1 1 1 1 1 1 1 1 1 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

TIME (MINUTES)

Figure 9. Pressure history of LOX transfer for an initial receiver tank

temperature of 200 °F (366.3 K)

47
4. 3 ET Temperature

Since the previous study [1] indicates the ET fluid is subcooled, the

default initial temperatures in this study were between the melting line and

the liquid-vapor boundary [3,4,5]. Increasing the ET initial temperatures

cause longer transfer times, while additional cooling accomplishes the

transfer faster. As the melting line temperature of either propellant is

approached, failure of the Fluids Pack [2] routine occurs. When the

temperature reaches the vapor-liquid boundary, the simulation stops due to

vapor induced cavitation. Because the transfer of LH 2 is pressure induced,

the transfer times are significantly affected by warmer ET temperatures.

Additional cooling time is required before the switch to the transfer mode

through the main piping.

4.4 Pipe Size and Pump Requirement

When the values for line size and pump power suggested by Brux and Stefan

[1] are used in the model, the time required to transfer the nominal quantity

of either propellant is less than 3 minutes. Because the mated coast period

after MECO probably will be somewhat longer than this, transfer times of

approximately 8 minutes or less appear reasonable. Such transfer times are

obtained with a number of cases where the transfer pipe diameter or the pump

size is changed. Figure 10 illustrates these changes.

If the LOX default pump size remains unchanged at 4 HP (2982.8 W) while

the line size is reduced to 2 inches (5.1 cm), the transfer time is slightly

less than 7 minutes. When the pump size is reduced by half, the transfer time

is less than 4 minutes for a 3-inch (7.6 cm) diameter pipe. Line sizes of

48
Transfer Piping Diameter, cm

0 2 4 6 8 10

Transfer Piping Diameter, in Figure 10a. Effect of varying the pump or transfer line siz

(default: 4 HP (2982.8 W), 4 in (10.2 cm))

Transfer Piping Diameter, cm

5 10

Figure 10b. Effect of varying the pump or transfer line siz

(default: OHP (0W), 5 in (12.7 cm))

49

es, LOX

es, LH^
approximately 1 inch (2.5 cm) appear to restrict the flow too much and cause

venting in the receiver tank and extremely long transfer times. A 6-inch

(15.2 cm) line size promotes a fast transfer of the remaining LOX propellant,

but it also is heavy; no further study of this line size was done. Since the

smaller line sizes would be lighter, easier to design around the existing

equipment, and less costly, reducing the line size from the default value of 4

inches (10.1 cm) to 3 inches (7.6 cm) is a reasonable exchange for the increase in transfer time. A pump size of 2 HP (14914.4 W) would not tax the

energy requirements in the system.

Similar results are seen for LH 2 scavenging. A reasonable transfer time

of slightly more than 7 minutes is obtained when a 3-inch (7.6 cm) line size

is used without pump assist. However, there appears to be too much flow resistance in smaller line sizes, even with the assistance of a pump. Hence,

longer transfer times are seen for these cases, even when a large pump is

used. When a 2 HP (14914.4 W) pump is used with 3-inch (7.6 cm) piping, the

time is reduced to slightly less than 6.5 minutes. Reducing the line size to

3 or 4 inches (7.6 or 10.1 cm) and pressurized transfer of LH 2 is an optimum

combination for the system.

4.5 Limitations

Accuracy for the results is limited by the size of the time step used in

program. When a very small step is used, the amount of computer time required

is large and consequently quite costly. Thus, the time steps used in the

previously discussed analyses are large enough to allow speedy computation,

yet small enough to yield reasonable accuracy. When the time step is reduced

by a factor of seven in SUBROUTINE COOL and by a factor of thirteen

50
in SCAVAG , the total time required to transfer LOX propellant changes by less

than 1.5 percent. However, the computer time required for this run increases by a

factor of 80.

5. SUMMARY

We have developed a computer model to investigate the scavenging of cryogenic propellant from the ET to shuttle mounted receiver tanks in the cargo

bay. Based on the requirement that sufficient thrust exists to settle the

liquid in the ET, the model predicts the successful transfer of liquid oxygen

and hydrogen in short periods of time, typically less than 2.5 minutes for

both LOX and LH 2 using the default parameters in the program. A parametric

analysis was performed to evaluate the effects of heat fluxes to various

system components, prechilling the receiver tank, and line and pump size

variations.

Moderate to large heat fluxes affect the pressurized transfer of LH 2 more

than the pump-assisted transfer of oxygen. Heat leaks to the ET increase the

pressure, and thus speed up the transfer of LH2

. Heat leaks to the piping or

receiver tank slow down the transfer of both propellants due to additional

receiver tank chilling demands, and cause venting at sufficiently high fluxes.

Prechilling the receiver tank for LH 2 is a critical requirement. The

LH2 receiver tank must be approximately -290 °F (94.1 K) in order to transfer

the fluid without venting. The LOX receiver tank can be close to 300 °F

(421.9 K) without the significant venting of fluid.

Line and pump size selection are dependent on the time allowed, the

piping design constraints and energy demands of the transfer system.

51
Pump-assisted transfer in the LOX scavenging is needed, and by using a 2 HP

(1491.4 W) pump and a 3-inch pipe diameter, a relatively lightweight, fast

system can be used. Liquid hydrogen can be transferred by pressure difference

in a 3-inch line. The smaller line and pump sizes allow the transfer to be

completed in less than 8 minutes.

52
APPENDIX A

Derivation of single-phase receiver tank equations:

First Law

dU = dQ total

+ h

l

dm

l + h

2

dm

2

Mass Balance dm = dm^ + dm^

By applying the mass balance to the system and assuming h = the first law

may be expressed as:

mdu + udm = dQ^. ^

-| + h-^dm^ ~ h(dm^ - dm)

„ d^total . h

l

dm

l

h(dV dm) udm

du = + - — - -

j ^total , m

l , u ux , dmPv

du = + (h, - h) + m m

v 1 m

(A. 1)

Because we wish to find temperature as a function of mass flow we next

expand du. The total differential energy equation with respect to temperature

and density is given by

du = ( —^

dT + p

3u^ d£

3p

du = C dT - v/Pl . 3v

T

By using the thermodynamic relationship

du = Tds - Pdv

we can obtain

u ||| = TV

3s

dv

- Pv . T

The definitions for and the Gruneisen parameter 4> are

Cv

= Tl 3s

31

= £(§I

r\*P

(A. 2)

53
(A. 3)

and the chain rule gives

Jp) = 4> TC - -

\3v /j r v p

Equation (2) then becomes

du = C dT - (4>T

C

v

Y v

Ps dm

p' m

Combining Equations (1) and (3) and solving for dT yields:

C dT - (4>T C

- -) — = -

Q

-tot1 + — (h-. - h) +

v v p' m m m

v 1 m or

dT =i

m

(h-. - h) dQ, . , (4>Tdm + ^ ) dm^ +

a (A. 4) v v

The heat flux is the sum of the heat leak through the tank and the heat

in the wall of the tank,

dlWal = dQ

+ d(

5w

dQx = - m C dT w w pKw

Substituting these expressions into the temperature equation yields the

following expression:

dT + m C w pw dT = -

C m

v m \4)Tdm + oy h)

d + dg

Upon rearrangement the following relationship is obtained:

dT = pTdm + ( h-^ -h)dm^/C

v

+ dQ/C^

m + m C /C w p v *w

(A. 5,3)

We next wish to find pressure as a function of mass flow. The total

differential energy equation with respect to pressure and density is given by

du =(±)p( dJ) 6P + p(P) & . 3P/ p \ap/

p p

54
The first term on the right-hand side contains the Gruneisen parameter

which is also defined as

= m

The second term on the right-hand side may be expressed with the heat of

expul si on

6 = - (A. 6)

and by using the definition of enthalpy to give

The differential energy equation may then be written as

du = \ dP - (0 - -)

^ . (A. 7)

P4> V p / p

Combining Equations (A.l) and (A. 6) and solving for dP when dm-^ = dm

yields the following expression:

dP = ^ (0 [0 + h

1

- h] dm + <J)(dQ - mw

CwdT)j . (A. 8)

When dm^ is not equal to dm, there is flow through the vent. Thus, dP = 0 and

dm

[(h - h

1

)dm

1

- dQ + m^dT]

_

(A. 9,5)

55
Appendix B

Derivation of two-phase receiver tank equations:

First Law

dU = dQ - dW + I h

1

dm

1

Since there is no work done, the first law may be expressed as: Vu£ + m

v duv + Vm£

+ uv dm

v = dqt0 tal

+ h

l

dm

l

+ h

2

dm

2 (B - X)

Continuity

dm^ + dm^ = dm^ + dm^ (B. 2,7)

Constant volume

v„dm„ + m n dv n + v dm + m dv = 0 . Z Z Z Z vv vv

Solving for dm^

dm

2

1

(m-.dv,, v + m dv ) Z Z v v

y

Let

(B. 3,9)

The equation for the differential mass of the liquid in the tank is:

v dm. = - —- dm - — £ U

£

U V

£

m. 9v

+ m

£

\ 9p

fZ

V

\ ap

dv

v J dP (B. 4)

Substituting Equation (B.4) into Equation (B.2) produces the following expression:

v

v

vZ

dm

v + dm

v + m

v dP = dm^ + dm^ .

56
Solving for the differential mass of the vapor:

dm =

v

dm^ + dm2 +

3\> dv

y w* + "vWv dP

(1 ' W

(B.5)

Substituting Equation (B.5) into Equation (B.4), we obtain the following

equation for dm^

dn

v

=

~( v

v /vg)( dml + dm2^ ‘ vz y (

3 p 1

+ m

v( ap)v

dP

a - VV

(B. 6,10)

Combining Equations (B.l), (B.5) and (B.6), we obtain

Mi)£

dP + m»(ip)

udP " u*

v dm, + dm 0 v 1 2

(1 W

dv \ dV

y y\^k * m

',l 8P/v dP

(i - vv

dm-^ + dm

2

J v d “ VV

1 /av\ / av ^

m

£Va P/£

+ m

v \3P/v dP

(i - »/V

= d() total

+ h

l

drn l + h

2

dm

2 (B.7)

We can solve Equation (B.7) for the differential pressure when there is no

venti ng:

dP =

h

l

- u v + ^

(u£h

l

) dm, + dQ. . ,(1 - v /v„)

1

x total v v V

F(p)

(B. 8,11a)

57
where

When there is venting, the pressure is constant. Since dP = 0, the following

equation is obtained when Equation (B.7) is solved:

(

v dm^ + c* m

2 \ /

^m

l + ^m2 \

\

(i - w] \

Uv (i wj

+ dQx

- m C dT + hudm, + h 0 dm 0 . w w 11 2 2

Finally, an expression for the differential mass through the vent is obtained:

A n£ v, dm

2 =

v

u + h, (1 - —

)

V 1 V

dm

1

+ d(3 O - T?

V

(hv - h„) —

v r v, (B. 10,12)

58
Appendix C

Tank Material Physical Data

INC0NEL*[12]

oo.ooc

0,000

'DOC

I 10 100 50C

Temperature, K

*Such recommendation does not imply recommendation or endorsement by the

National Bureau of Standards.

59

Specific

Meat,

Rfu

lb
SPECIFIC

HEAT.

10 3

Btu/(lb

m

°FJ

ALUMINUM [13]

TEMPERATURE, K

4 6 8 10 20 30 40 60 80 100 200 300

4000

2000

1000

600

400

200

100

60

40

20

10

64

2

1

0.6

0.4

0.2

0.1

0.06

_i_! I— L-J 1 J J 111! 1.1 _ I.J l I II 1 j ilii.il •450 -440 -420 -400 -300 -200 -100 0 80

TEMPERATURE, °F

60

SPECIFIC

HEAT.

J/(kg

K)
Appendix D Conversion factor calculation

The conversion factor C for Equation (26) may be derived as follows

where

_ AP P7T 2 D

5 fL(dm) 2 M

AP = atm

P = gmol/i

D = cm

L = m

M = g/gmol

Therefore

,

32 c = (atm)(qmol/l)(cm 5

) (m)(gmol/s) 2 (g/gmol

)

lm 1 Si 100 cm / 0. 001 m

3 kg m2

J s

2

32C = 3.158 latm )(s 2 )(cm 5

) (m)(£)(g)

61
Appendix E

Derivation of the supply tank equations:

First Law

dU = dQ - dW + Ih.m.

The first law can be written for both phases, and when the mass of vapor is

held constant we have the following expression:

vapor r phase r m du = dQ - P(m dv ) V V V V

Upon substitution and rearrangement , the vapor phase enthalpy equation becomes:

For the liquid the first law may be expressed as

liquid phase m^du^ + u^dm^ = dQ^ - Pm^dv^ - Pv^dm^ + h^dm^ .

By using the previous substitution and rearrangement , the liquid phase enthalpy

equation can be written as

Si nee

then dh - v dP = du + Pdv . v v v v

(E. 2,13b)

Vol ume

Since the ET volume is constant the following expression is used:

V = constant = + v

y m

v

62
Upon rearrangement,

Vm£

= ' (mA + m

v dUv

) (E - 3)

The total derivative for volume with respect to pressure and enthalpy is

expressed as

du = (!)p dh + (i)

h

dp • (E4)

We recall the definition for the heat of expulsion 6 and substitute it for the

first term in the total volume derivative as follows:

0 = -p v

P

!h)

p dh = I

dh •

To elucidate the thermodynamic nature of the second partial derivative,

the following thermodynamic identity is used:

3 p )h Wp Wv

= ' 1 •

The term 9y

3P can be expressed in terms of 0

/ay\ / 3y \ /3y\ _ y

/ 3h\

\aP/

h

" \ ah /p Vap/

v

0 \aP/

v

‘

The definition for the Grtineisen parameter can be used with the first law to

eliminate the remaining partial derivative. The GrLineisen parameter is:

(f> = -

P

3P

au

= \>\(9P

Vau

By writing the first law in terms of derivatives with respect to pressure at

constant volume, we can make the following substitutions:

63
+ V §h\ Jbu\

ap/' \3p/

V

v V

= £

+ V

4>

= V

0 + 1

The second term in Equation (E.4) can be expressed as:

3v\ v /v (0 + 1 ) apj, "

e

Equation (E.4) can now be expressed by the following relationship

dv = 5dh - 1} dP . (E.5)

We can substitute Equation (E.5) into (E.3) to obtain the following

relationship:

dm. dh. m v dh

£ _ £ v v v m

£ " ’ 6£

' Vi 6

V

£ / d> + 1

m v

z v v VA fij_l

4> ; dP . (E. 6 )

By solving Equations (E.l), (E.2), and (E.3) simultaneously, a relationship for the ET pressure is found:

dP =

+ VQy +

1 _ ^£

m

£ VA ®£ m£

\) £ m \> z v v

(E. 7 ,14)

0.0. H1.V.0 6

£

Y£ £ £ VY

V

An expression for the temperature of the liquid can be obtained by using

the liquid enthalpy equation (E.2) and the total enthalpy derivative.

64
The total enthalpy derivative with respect to temperature and pressure is

given by:

T

dP + (E.8)

The second partial derivative in Equation (E.8) is the definition of the conThe definition for the bulk thermal expansivity a of a fluid is given by [7]

By substituting for the partial derivatives as discussed, Equation (E.8) may

be written as follows for the ET liquid phase

dh

£ = v (1 - of £

) dP + CpdT .

By substituting Equation (E.2, for dh

£

in the previous equation and

solving for dT, the temperature equation is given by the relationship

The partial derivative may be expressed as

(E. 9,15)

65
Appendix F

Plotting routines

The data which describe the transfer of fluid are stored in file PSDATA

(see printout of file in Appendix C). These data are used in two plotting

programs called PROGRAM PLOT and PROGRAM DEMO. Both programs are written in

FORTRAN IV and are fully described below. The data file is described first.

FILE PSDATA/TAPE8

The first four lines of the file are data points for identifying and

initializing the plots for either PROGRAM PLOT or DEMO. The first line of

data contains four identifying parameters -- the transfer line size, pump

size, and the initial receiver tank temperature and pressure. The second line

contains the alphanumeric name of the propellant, HYDROGEN or OXYGEN. The

total number of data lines, N, is written on the third line. Finally, the

fourth line holds the lower and upper limits for each of the plots to be

drawn. The order of these pairs of values is the time, receiver tank

temperature and pressure, the flowrate, the mass of vapor, mass of liquid,

total mass of fluid transferred, the quality of fluid in the ET, and the

quality of fluid entering the receiver tank.

Following these lines are the N lines of data. Each entry holds the data

describing the transfer for each increment of time. The values in each line

are the elapsed time, the receiver tank temperature, receiver tank pressure,

the flowrate, the mass of vapor, liquid, and total mass of propellant

transferred, the ET fluid quality, and the quality of fluid entering the

receiver tank.

66
PROGRAM PLOT

The NBS computer system in Boulder has a mathematics library called

STARPAC from which subroutines may be called to perform assigned tasks. For

program PLOT the SUBROUTINE PPC is used to produce four plots and is accessed

by the statement CALL PPC(A1, A2, A3, A4, A5, A6, A7, A8, A9, A10). Each

parameter is described as follows:

A1 Array containing the value to be plotted on the vertical axis.

A2 Array containing the values for the elapsed time during the

transfer to be plotted on the horizontal axis.

A3 The number of lines of data to be read.

A4,A5,A6 Parameters describing whether the plot is to be logarithmic,

the size of the plot is to be altered, or the plot is to be

reprinted. All are set equal to zero.

A7,A8 Lower and upper values for the vertical axis.

A9,A10 Lower and upper values for the horizontal (time) axis.

PLOT first assigns single array dimension sizes for the time, temperature, pressure, flowrate, mass of vapor, and mass of liquid. Second, the

first four lines of data are read into appropriate variable names. Following

these assignments the data points are read into the dimension arrays.

The first call to PPC enables a plot to be drawn of the receiver tank

temperature as a function of time. The second call to PPC is for a plot of

the receiver tank pressure as a function of time. The third call plots the

mass of propellant in the vapor phase as a function of time. The fourth call

to PPC produces a plot of the mass of liquid phase propellant as a function of

time. Each plot has an appropriate heading. There are 10 vertical and horizontal axis divisions for each plot.

When batch control procedure SUBCOM is used, the plots are located after

the output from program SCAVAG and all output subsequently are written to

67
TAPE6 and PSOUT. Should the operator choose to have the output separated, two

other batch control procedures are used. First, SCAVAG is run with NOPLOT, in

the same manner as has been described in the main text for SUBCOM. Output is

written to TAPE6/PS0UT and PSDATA as before. To generate the plots for the

transfer with program PLOT, control procedure LIBPLOT is used. Output is

directed to TAPE6 and stored in filename TRACE. (See Appendix G for the program, data, control procedure listings, and sample plots.)

PROGRAM DEMO

The DISSPLA graphics package [15] is available at NBS in Boulder and at

NASA-JSC. Since it produces high quality plots and is quite versatile,

DISSPLA was chosen for graphic display of some of the results of this study.

It is used by program DEMO to produce seven plots. Two plots, each allowed

half of a standard page, are placed on the first three pages, and the remaining plot is located on the upper half of the fourth page.

DEMO assigns dimension sizes and variable names in a manner very similar

to that of program PLOT. However, additional arrays and variable names are

required for the parameters used in the DISSPLA subroutine calls. After the

lower and upper bounds for each of the plots are read from PSDATA, DEMO calculates the division size for the axes of each plot. After the data points are

read into their respective arrays, the program is fully initiated and proceeds

with a succession of DISSPLA subroutine calls which set up and plot the curves.

A full description of each subroutine can be found in the DISSPLA user's

manual. (The program listing and sample plots are located in Appendix G.

)

Several items are unique to program DEMO. Whereas PLOT reads the first

line of data into four dummy variables, DEMO uses these data as identifiers

located in the corner of the first plot. The name of the propellant is not

used in PLOT, but in DEMO it is used in the heading for each page. In

68
addition to the four plots which are generated by both PLOT and DEMO, DEMO

also plots the total mass of propellant transferred, the flowrate into the

receiver tank, and the percent of vapor and liquid phases in the receiver

tank, as a function of time.

DEMO is run interactively by the operator. Instead of storing the output

in files which are accessed at a later time (i.e., batch operation, SCAVAG

with control procedures SUBCOM or NOPLOT, and PLOT with control procedures

SUBCOM or LIBPLOT), output is generated immediately at the terminal or other

output device. To run DEMO at NBS, the operator types in at the terminal

GET, DEMO

DEMO

or BEGIN, DEMO, DEMO

The first line instructs the computer system to retrieve program DEMO from

storage and place it in the local mode and ready for use. When DEMO is typed,

the procedure for running the program is activated. The alternative command

identically performs both statements. The procedure is located in the lines

prior to the program statement and uses a sequence of control statements

similar to those contained in the batch control procedures SUBCOM, NOPLOT, or

LIBPLOT.

Output is generated at the terminal screen when the appropriate call is

made and graphics capabilities are available. Other output options are a

multiple pen plotter or microfilm. The first page, or two plots, are drawn

automatically. The operator types

COPYBR , Z

to have each subsequent page drawn at the terminal or the pen plotter. All

plots are automatically drawn on microfilm.

69
Appendix G

Program listings and sample plots

70
(->r>ooo<~>or>or>

r»or>r>r>or>oor>

o

r»

o

or»o

r»

o

o

o

or»oo

PROPELLANT SCAVENGING PROGRAM-COMBO

PROGRAM SCAVAG< INPUT,TAPE5*TAPE6,TAPE7,CUTPUT-TAPE6*TAPE8}

C THIS PROGRAM SIMULATES THE FILLING OF A RECEIVER TANK IN LOW G

C USING A SUPPLY/EXTERNAL TANK.

C COMMON/ PAR AM/ M W> MW AL L # 0# VOL » OP I P E » OE T * TOT AL # P VE NT

COMMON /SUB/ FLO Wl, FLO W2, PRESS, TEMP*TIME*HET

COMMON/FLOW/ DIAM*DET#TET# PET, LENGTH* PMETER

COMMON/ NOZZLE /C DI AM, N OZ D I A, HE AD I A , NNO Z, CON ST, C DLE NG

common/pump/ power*eff

COMMON/ PLOT/ NPLOT, X,Y1,Y2, Y3, YA, Y5, Y6* Y7*YB

common/prop/ngas

common/etank/eti IQ,ETVAP#VET,ETO

COMMON/ PROB/DUMP

REAL MV AP, ML 10, MW, MW ALL , L ENGTH, NOZDIA

REAL X(600),Y1(600),Y2(600),Y3(600)*Y4(600)*Y5(600)# Y6(600)

,Y7(fe00),Y8(600)

THE NAMELIST "NAME" CONTAINS ALL PARAMETERS THAT CAN BE VARIED

FROM DEFAULT VALUES.

NA“ELIST/NAME/PET#TET,OET*TOTAL*DIAM,NELBOW*NANGLE*NGATE#

N GLOB E, NBUTT *L EN G TH, ME TE R,OPIPE* POWER* VOL, M WALL* TEMP, PR ESS,

P VENT # Q,CDLENG*HEADIA,NNDZ*NOZDIA* VET* CON ST NGAS • 1 FOR HYDROGEN AND 2 FOR OXYGEN CHANGE IN NAMELIST "FUEL"

NAMCLIST/FUEL/NGAS

NGAS • 1

PE AD ( 7, FUEL

)

INITIALIZE FLUID PROPERTIES WITH FLUIDS PACK SUBROUTINE.

IF(NGAS.E0.2)G0 TO 1 CALL DATA P H2

INITIALIZE MOLECULAR WEIGHT

MW 2.0159A

SET DEFAULT VALUES FOR THE SIMULATION.

INPUT PARAMETERS FOR SUP°LY TANK!

PET • TANK PRESSURE# PSIA

TET TANK TEMPERATURE# DEG. F OET - HEAT FLUX INTO SUPPLY TANK, BTU/HR

TOTAL TOTAL PROPELLANT IN SUPPLY TANK* POUNDS

VET TANK VOLUME, CUBIC FEET

PFT - 32.

TET -A2 5 . OET 90000.

TOTAL • 3098.

VET - 53518.

INPUT PARAMETERS FOR PIPING BETWEEN TANKS*

DIAM - PIPE DIAMETER# INCHES

NELBOW NUMBER OF RIGHT-ANGLE ELBOWS

NGATE - NUMBER OF GATE VALVES

NGLOBE NUMBER OE GLOBE VALVES

NANGLE NUMBER OF ANGLE VALVES

NBUTT » NUMBER OF BUTTERFLY VALVES

LENGTH - LENGTH OF STRAIGHT PIPE# FEET

METER • NUMBER OF FLOW METERS

71
oooooooo

onnoonnon

o

o

r> OPIPE HEAT FLUX INTO PIPE# BTU/HR

POWER • PUMP POWER# HP DIAM • 5. NELBOW 10

NG ATE 0 NGLOBE - 2 NANGLE » 0

N BUTT 0 LENGTH - 70.

METER - 1 OPIPE « 50*00.

POWER 0.

INPUT PARAMETERS FOR RECEI

VOL • TANK VOLUME# CUBIC

MWALL TANK WALL MASS#

TEMP - INITIAL RECEIVER

PRESS INITIAL RECEIVER

P VENT • RELIEF VALVE VEN

0 HEAT FLUX INTO TANK#

VER TANKI

FEET

POUNDS

TANK TEMPERATURE# DEG F PRESSURE# PSIA

T PRESSURE# PSIA

BTU/HR

VOL - 780.

MWALL 975.

T F M P - -290.

PRESS • IB.

P VENT • 30.

0 - 0 . INPUT PARAMETERS FOR FLOW SIMULATION AND COOL-DOWN PIPING*

COLENG • LENGTH OF COLL-DOWN PIPING HEADER

NN 02 - NUMBER OF NOZZLES

NOZDIA DIAMETER OF OR I F IC E /N OZ Z L E # F E ET HEADIA » DIAMETER OF HEADER AND COOL-DOWN PIPING# INCHES

CONST 1/ORIFICE CONSTANT. ORIFICE CONSTANT • 0.61

C

C

CDLENP 20.

NNOZ 6 CONST - 1.639

NOZDIA 0.5

HEADIA 2.0

GO TO 2 CALL DATA 02

MW » 31.99B8

PET » 20.

TET -315.

OFT 0.

VET • 19786.

TOTAL 6270.

DIAM • 4.

NELBOW 20

NG ATE • 0 NGL09E • 2 NANGLE 1 NBUTT 0 LENGTH 100.

METER • 1 OPIPE • 104*00.

POWER 4.

VOL • 300.

MWALL • 350.

72
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TEM«> 60.

PRESS - 1.

P VENT • 30.

0-0.

CDLENG • 20.

NNOZ 6 CONST • 1.639

NP7DIA 0.25

HEADIA > 1.0

C

2 CONTINUE

READ IN VALUES OF SIMULATION PARAMETERS THAT ARE TO BE DIFFERENT

FROM THE DEFAULT VALUES.

R EAD( 5, NAME ) WRITE SOME SIMULATION PARAMETERS TO BE WRITTEN ON DISSPLA PLOTS

FOR SIMULATION IDENTIFICATION.

WR ITE ( 8 , * ) DIAM, POWER, TEMP, PRESS

WRITE SIMULATION PARAMETERS ON OUTPUT.

IF (NGAS.E0.2)G0 Tn 4449

WPITE (6,4400)

4400 FORMAT (1H1>*HYDR0GEN TRANSFER*)

GO TO 4499

4449 WR I TE ( 6 , 4450

)

4450 FORMAT! 1H1, *OXYGEN TRANSFER*)

4499 WR ITE ( 6, 4500) PET, TET, TOTAL, OET

4500 F0RMAT(1H1,*SUPPLY TANK INITIAL CONDI TI ON S t * /, 5 X, *PR E S SUR E • * #F10.3,* PSI A*/,5X,*TEMPERATURE *,F10.3,* F*/,5X,

* m 4 S S - *, F10. 2, * POUNDS*/, 5X,*HEAT LEAK - *,

FI?. 3,* BTU/HR*)

WR I TF (6,4600) PR E S S, TEMP, P VEN T, VOL , MW AL L ,

0

4600 FORMAT! * RECEIVER TANK INITIAL COND ITI ONS » * / , 5 X,

+PRESSURE - *,F10.3,* PS I A * / , 5 X, *TEM PE R ATUR E • *,F10.3,

* F*/,5X,*VENT PRESSURE « *,F10.3,* PSIA*/,5X,

*TANK VOLUME • *,F10.3,* CUBIC FEET*/,5X,

*TANK WALL MASS *,F10.3»* POUNDS * /, 5 X, *HE AT LEAK *,

F12.3,* BTU/HR*)

WRITE (6,4700) D I A M, L ENGTH, NEL BOW, NG ATE, NGLOBE, N ANGLE , NB UTT,

METER, OPIPE, POWER

4700 FORMAT!* TRANSFER PARAMETERS «*/, 5X, *PIPE DIAMETER *,

FB«3»* INCHES*/, 5X,*LENGTH OF STRAIGHT PIPE *,F8.3,

* FEET*/, 5X, 13, + ELB0W(S)*/,5X,I3,* GATE VAL VE ( S )* / , 5X , 1 3,

* GLOBE VALVE($)*/,5X,I3»* ANGLE VAL VE ( S ) * /, 5 X, I 3,

* BUTTERFLY VAL VE ( S ) * / , 5 X, 13 , * FLOW METER ( S ) * / , 5 X,

*HE AT LEAK INTO PIPING » *»F12.3,* BTU/HR*/, 5X,

*°UMP POWER • *, F5.1,* HP*)

WRITE (6,4800)CDLENG,NN0Z,N07DIA,HEADIA

4800 FORMAT!* COOL-DOWN PARAMETERS «*/,5X,*LENGTH OF PIPING

1, FB .3, * FEET*/,5X,*NUMBER OF NOZZLES « *,I4,

1/,5X,*N0ZZLE DIAMETER « *,F8.4,* INCHES*,

1/5X,*HE ADER DIAMETER *,F8.4,* INCHES*)

CALCULATE EQUIVALENT LENGTH OF PIPING.

LENGTH - LENGTH 4 FLOAT ( NE L BOW) * ( 2 . 5273 8*D I AM* . 41 428 6

)

4 + FLOAT(NGATE)*(.57083*DIAM-.O125)4FLOAT(NGLOBE)*

4 (38.0595*DIAM*.10714)4(FLOAT(NANGLE>4FLOAT(NBUTT)/8.>*

4 (14. 3452*DIAM-1. 17857)

C CONVERT ALL PARAMETERS AND VARIABLES FROM ENGLISH UNITS INTO

73
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non

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ooooo

ooo

oo

o

o

o SI UNITSI PRESSURE - ATM, TEMPERATURE - DEGREES KELVIN, HEAT LEAKS - JOULES/SEC, MASS - GRAM-MOLES, PI»E DIAMETER - CM, PIPE

LENGTH - METERS, PUMP POWER - JCULES/SEC, VOLUME - LITERS,

TIME - SEC.

P F T - PET/14.696

TET (TET+460. )*5./9.

OET ® 0ET*1054. 35/3600.

VET - VET*28.317

TOTAL » TOTAL *454 » /MW

DIAM D I AM *2 • 54

LENGTH LENGTH * .3048

PMETER • FL0AT(METFR)/14.696

OPIPE » OPI PE*1054. 35/3600.

POWER P0WER*746.

VOL VOL *2 0.317

MWALL « MWALL*4*3.59

TEMP » (TEMP+460.)*5./9.

PRESS PRESS /14. 696

P VENT PVENT/14.696

0 - 0*1054.35/3600.

C DL ENG - CDLENG*0.3048

CDIAM - HEADIA*2. 54

INITIALIZE THE FLUID PROPERTIES

DET • FIND D(PET,TET)

HFT - ENTHAL(PET»DET,TET)

FRACT TOTAL/VET/DET

TETS4T FINDTV(PET)

ETVAP - FINDD(PET,TETSAT*l.E-3)+VFT*(l.-FRACT)

OBTAIN OUALITY OF SUPPLY TANK FLUID

CALL CHECK(HET»PET,TET,ETO)

initialize TIME

TIME - 0. INITIALIZE COOL-DOWN NOZZLE PRESSURE DROP

INITIALIZE FLOWRATE. THE FLOW IS DUE TO PRESSURE DROP BETWEEN THE TANKS

F CUES S FLO(PRESS)

F L 0W1 • PUMPFLO( PRESS, FGUESS)

INITIALIZE VENT FLOWRATE

FL0W2 - 0.

INITIALIZE TOTAL AMOUNT OF MATERIAL VENTED AND AMOUNT OF VAPOR

PRESENT IN THE RFCEIVER TANK.

X VENT 0.

M V A P 0.

INITIALIZE COUNTER FOR OUTPUT TO GO TO PLOTTING ROUTINE.

N PLOT • 0

74
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o

n

n

o

oooo

o

o

o

o

o

o

o

o

oooo INITIALIZE VENT FLAG TP INDICATE THAT THE RECFIVER TANK VENT

IS CLOSED.

N VENT - 0 INITIALIZE PROGRAMED STOP PARAMETER

DL'MP - 0.

CALL SUBROUTINE THAT MODELS THE COOL-DOWN CF THE RECEIVER TANK UNTIL

TVO PHASES ARE PRESENT IN TH F RECFIVER TANK.

CALL COOL(MVAP,XVENT,DPPESS)

NPRT • 0 CALCULATE THE ENTHALPY OR THE FLUID ENTERING THE RECEIVER TANK

AND CHECK THE OUALITY OF THE FLUID.

H] HET+OPIPE /FL 0 V 1 + PORFP/ELOWl

CALL CHECK(H 1 ,PRFSS»TEmp,TANKO)

SET THE TIME STEP FOR THE SIMULATION. NTTEi OTIME 2 COO./FLOW 1 FOR LH? AND 3 DO. /FLO Wl FOR LOX ON NASA-JSC COMPUTER

D T

I

M E - VOL/FLO Wl/ e OO.

IF { n o a s , EO . ?)DTI*E - DTIME/ 2 . I F { NG A S .EO. 1 IOTIME - DTIME‘ 2 . D T I MC . OTIME + 5 C.

. DT I ME • DTIME/ 3 . 1*159

INITIALIZE THE AMOUNT OF LIQUID PRESENT IN THE RECEIVER TANK.

MLIO = 0.

DLIO » FIND D ( PPESS+1 .F-3, TEMP)

D V A P * FIND 0<PPFS$-1.E-5»TF M P)

LOOP FOR TWO-PHASE SIMULATION.

I - 0 1000 CONTINUE

I 1 + 1 OBTAIN VAPOR AND LIOUID ENTHALPY (J/GMOLIAN" INTERNAL ENERGY ( J / G ^ OL

)

H V A P « ENTHAL(PPESS-1.E-*;»DVAP,TEMP)

HLTC - ENTHAL(PRFSS+1.E-5»DLI3»TEMP)

IJVAP « HVAD-PPESS*10i.??7/DVAP

ULIO - HLI0-PRESS*101.327/DLIQ

C CALCULATE FUNCTION FOR DELTA P.

C FP - ML 1 0 * ( (1 ,-DL IQ/DVAP) *DUD p L ( PRESS ) CL IO*DVDPL ( PRESS

)

+ *(UVAP-!!LI0))*MVAP+({1.-DLI0/DVAP)*0UPPV(PPESS)

+ DLIQ*DVDPV( PRESS IMUVAP-UL IQ) ) F P P « FP + MW ALL*CW AL L (TEMP ) *DTDP ( PRE SS )*

(l.-DLIO/DVAP)

DELTAT - DTDP(PRFSS)*DPRESS

C

C CALCULATE DELTA P C OPPPS^ - ( ( Hl-I'VAP + DL IO/DVAO* (ULI0-H1 ) ) FLOWl + ( 0)

+ (1 . — DL IO/DVAP) ) /FPP

32 CONTINUE

75
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ooo CALCULATE NEW PRESSURE AND OBTAIN NEW TEMPERATURE.

PRESS PRESS DPRESS+DTIME

TEMP - FIND TV (PRESS)

RECALCULATE THE FLOWRATE

FL FLOWl*MW*. 13216

FLOW « FLOWl

FLOW1 « *»UMPFLO(PRESS»FLOW)

FL FLOW1+MW*. 13216

17 CONTINUE

CHECK FOR RELIEF VALVE OPENING

FLOW2 « 0.

179 CONTINUE

IF (PRESS+DPRESS+DTIME .LT. PVENT*.999) GO TO 15

IF (NVENT . EO . 0 .AND. PR ESS+DPP E SS+DTI ME .LT. PVENT*1.002)

+ GO TO 15

CALCULATE THE VENT FLOWRATE

FL0W2 - (0* (1 .-DLI0/DVAP)-(UVAP-H1-DLI0/DVAP*(ULI0-H1)

)

RFL0W1 )/ (DLIO/DVAP*(HVAP-HLIQ)

)

CHECK TO SEE IF THE SYSTEM IS VENTING PROPERLY

IF (FL0W2 .LT. 0.) GO TO AO

GO TO 1

A

AO DPRESS 0.

PRESS - PVENT

SET FLAG TO INDICATE THAT THE RECEIVER TANK IS VENTING AND

CALCULATE TOTAL MOLES VENTED.

NVENT - 2

X VENT XVENT-FL0W2*DTIME

GO TO 15

1A FL0W2 • 0.

NVENT 0

15 CONTINUE

CALCULATE NEW VAPOR AND LIOUID DENSITIES

DLION FIND D(PRESS*1.E-2»TEMP

)

DVAP FIND 0 (PRESS-1. E-5, TEMP)

IF(DLIQ/DLION .GT. 10.)G0 TO 231

DLIC DLION

231 CONTINUE

C

CC

CALCULATE CHANGE IN LIOUID MOLES AND ACTUAL NUMBER OF MOLES

IN LIOUID AND VAPOR PHASES AT T • TIME.

DMLIO - -DLIQ/DVAP+(FLOW1*FLOW2)/(1.-DLIO/DVAP)-DLIO*

(MLIO*DVDPL(PRFSS)*MVAP*DVDPV( PRESS) )*DPRESS/

( l.-DL IO/DVAP)

m L 1 0 - MLIQ + DMLIO*DTIME

M V A P - ( VOL-MLIO/DLIO)*DVAP

CHECK TO SEE IF THE RECEIVER TANK IS FULL OP IF(MLIQ*MVAP*XVENT .LT. 0.95*TOTAL)GO TO A5

A 6 IF(MLIO*MVAP*XVENT .LE. TOTADGO TO A

8

A 7 ML 1 0 MLIO-DMLIORDTIME

M V A P (VOL-MLIQ/DLIO)*DVAP

A 8 DTIME1 (TOTAL-( XVENT + ML IO + MVAP ) )/DMLIO

OVERFLOWING

76
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non

I F { DT I M F .IT. DTI ME1 ) GO TO 45

49 MLIO • MLI0*DMLI0*DTIME1

M V A P (VOL-MLIQ/DLIO)*DVAP

36 IF ( MV A P .GT. 0.) GO TO 35

CALL THE SUBROUTINE TO STOP THE PROGRAM.

NPLOT NPLOT 1 X(NPLOT) TIME/60.

Y1 (NPLOT) TEMP*9./5.-460.

Y2(NPL0T) • PRESSU4.696

Y3(NPL0T) • FL0W1YMH*. 13216

Y4( NPLOT) - MVAP*MW/454.

Y5 (NPLOT) • ML I OPMW/454

Y6 (NPLOT) Y4(NPL0T)+Y5(NPL0T)

Y7 ( NP LOT ) ETO

YB(NPLOT) TANKQ

CALL FULL (MLIQ» XVENT)

CHECK TO SEE IF ALL THE FLUID HAS BEEN TRANSFERRED.

CALL SUBROUTINE TO STOP PROGPAM.

35 NPLOT NPLOT + 1 X(NRLOT) - TIME/60.

Yl(NPLOT) • TEMP*<5./5.-460.

Y2 (NPLOT) PRESS*14.696

Y3(NPLCIT) - FL0W1*MW*. 13216

Y4 ( NP LOT ) MVAP+MW/454

.

Y5(NPL0T) - MLIQ+MW/454.

Y6 (NPLOT) - Y5(NPL0T) Y4(NPL0T)

Y7(NPL0T) ETO

Y 8 ( NP LOT ) » TANKO

CALL DONF (MLIO+MVAP, XVENT)

UPDATE THE SUPPLY TANK PROPERTIES .

45 ETLIO TOTAL-MLIO-MVAP-XVENT

CALL CHECK(HET»PET#TET,ETO)

CALL SUPPLYtDTIME ) CALL CHECK(HET,PET,TET#ETO)

INCREMENT THE TIME

TIME • TIME DTIME

CHECK TO SEE IF c L 0 W HAS STOPPED DUE TO RECEIVER TANK BACK PRESSURE

IN THE ABSENCE OF A PUMP.

IF (PRESS .GE. PET .AND. POWER .LT. ,05)G0 TO 63

CHECK THE FLOWRATE TO SEE IF BACK PRESSURE FROM THE RECEIVER HAS

STOPPED FLOW IN THE PRESECE OF A PUMP.

IF (ABS(FLOWl) .LT. .1) GO TO 63

GO TO 73

63 CONTINUE

NPLOT NPLOT 1

X ( N PLOT ) TIME/60.

Yl(NPLOT) « TFMP*9./5.-460.

Y 2 ( NPLOT) - PRESS*14.696

Y3 (NPLOT) • FL0W1*MW*. 13216

Y4( NPLOT) MVAP*MW/4 K 4. Y5 (

N

p LOT )

«* ML I Q* MW /4 54 .

77
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o

oo

o

o

Y6(NPL0T) * Y*(NPL0T)4Y5(NPL0T)

Y7(N°L0T) • ETO

Y8(NPL0T) TANKO

CALL PFAIL(MVAP4MLIQ,XVENT)

CALCULATE THE ENTHALPY OF FLUID ENTERING RECEIVER TANK AND OBTAIN

ITS OUAL IT Y.

73 CONTINUE

HI • HET+OPIPE/FLOWl 4 POWER/FLOW1

CALL CHECK(H1,PRESS,TEMP, TANKO)

•585

I F ( DUN P .NE. 1 • ) GO TO 505

NPLOT NPLOT 4 1 X(NPLOT) - TIME/60.

Yl(NPLOT) TEMP*9./5.-460.

Y2 ( NPLOT) PRESS*1A.696

Y3(NPLOT) FLOWl*WW*. 13216

YA(NPLOT) • MVAP4MW/A5A.

Y5 ( NPLOT ) MLIC*MWM54.

Y6(NPL0T) YA(NPL0T)4Y5(NPL0T)

Y7 (NPLOT ) • ETO

Y8(N°L0T) • TANKO

CALL PDATA(MVAP4MLIQ,XVFNT)

CONTINUE

WRITE RESULTS EVERY CHOSEN TINE INCREMENT.

N PPT • NPRT 4 1 IF (NPRT .NE. 1) GO TO 20

NPRT 0 NPLOT NPLOT 4 1

X ( NPLOT ) • TIME/60.

Y1 (NPLOT) • TEMP*9. /5.-A60.

Y2 ( NPLOT) • PRESS*1A.696

Y3 ( NPLOT ) - FL0W1+MW*. 13216

YA(NPLOT) - MVAP*MW/A5A.

Y5 (N°LOT) HLI0*MWM5*.

Y6(NPL0T) • YA(NPL0T)4Y5(NPL0T)

Y7 (NPLOT ) ETO

YP(NOLOT) TANKO

20 I F (NPLOT ,LE. 600) GO TO 1000

WR ITE ( 6, 1 53 ) 153 FORNATt/,* ARRAY LENGTH EXCEEDED*)

CALL PDATA(NVAP4Ml IO,XVENT)

END **************** ********* ******************************** ************ SUBROUTINE COOL ( M, X VENT# DPR ES S

)

THIS SUBROUTINE TAKES THE SIMULATION FROM TIME ZERO UNTIL

TWO PHASES ARE PRESENT IN THE RECEIVER TANK.

COMMON /FLOW/ DIAM,DET,TET, PET, LENGTH, PHETER

COMMON /PAP AM/ MW, MWALL,0, VOL, OPIPE,OET, TOTAL, P VENT

COMMON /SUB/ FL0W1,FL0W2, PRESS, T,TI*E,HET

common/nozzle/cdiam,nozdia,headia,nnoz,const,cdleng

COMMON/PUMP/ POWER, EFF COMMON /PLOT/ NPLOT, X,Y1,Y2,Y3,YA,Y5,Y6,Y7,Y8

common/etank/etliq,etvap,vet,eto

COMMON/PROB/DUMP

78
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o

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oooo

non

COMMON/PROP/NGAS

COMMON/NEG/IJK

REAL X( 600) #Yl(fc00)#Y2(600)#Y3(600)# YM600)#Y5(600)#Y6(600)

#Y7(600)»Y8(600)

REAL MW ,

WALL #M, LENGTH, CDL ENG# NOZDI

A

INITIALIZE PRINTOUT COUNTER# VENT FLAG AND SIMULATION LOOP COUNTER.

IJK - 2 NPRT 0

N VENT 0

KOUNT 0

K 0

INITIALIZE FLOWRATE BETWEEN TANKS# P'JMP EFFICIENCY AND DENSITY OF VAPO

IN RECEIVER TANK.

EFF - PEFF(FLCWl)

DENS FIND D(PRESS#T)

CALCULATE THE CHANGE IN VAPOR MOLES.

DM • F L OWl + FL 0V2

DT I ME VOL /FLOW1/800.

IFtNGAS .E0.2)DTIME-DTIMP/2.

DTI Mf . DTI ME /I . LOOP FOR SIMULATION

10 KOUNT - KOUNT 1 CALCULATE GPUENSIAN PARAMETER AND THE ENTHALPY OF FLUID ENTERING RECEI

TANK AND CHECK ITS QUALITY.

CALL PPHI(DENS#T#PHII)

GPU • PHII

HI HET+QPIPE/FL0W1 P0WER/FL0W1

CALL CHECK(H1#PRESS#T#TANK0)

OBTAIN ENTHALPY OF VAPOR IN RECEIVER TANK (J/GMOL)# HEAT CAPACITY AT CONSTANT VOLUME (J/GMOL/DEG K).

H - ENTHAL(PRESS#DENS#T)

CVAP - CV(DENS»T)

CALCULATE CHANGE IN VAPOR DENSITY AND RECEIVER TANK TEMPERATURE

WITH RESPECT TO TIME.

DDENS DM* DT IME / VOL

DT«(GRU*T*DM+ ( <H1-H)*FL0W1*0) /C VA P ) / ( DE NS* VOL + MW A LL *C WA LL ( T ) /C V A P

)

*DTI ME CALCULATE HEAT ABSORBED BY TANK WALL# HEAT OF EXPULSION AND CHANGE

OF RECEIVER TANK PRESSURE WITH RESPECT TC TIME.

OWALL -MWALL*CWALL(T)*DT/DTIME

THETA • TH ( DENS # T

)

DPR ESS -GPU* (THETA*PM+(H1-H) *F L OWl 4 040V A LL ) *DTI M

E

/VOL/101.327

CALCULATE NEW RECEIVER TANK DENSITY# TEMPERATURE AND PRESSURE# AND

INCREMENT THE SIMULATION TIME.

DENS - DENS + DDENS

T - T 4 DT

79
ono

ono

o

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n

oooooo

TIME « TIME DTI ME PRESS PRESS DPRESS

C RECALCULATE THE FLOWRATE

FLOW - FLOW 1

F L 0W1 « PUMPFLO(PPESS»FLOW>

FL • FL0W1**W*. 13216

11 CONTINUE

C F10W2 * 0.

C CHFCK TO SEE IF THE RELIEF VALVE HAS OPENED.

C IF (PRESS .LT. PVENT* • 999 ) GO TO 25

IF (NVENT © EG » 0 .AND. PRESS .LT. PVENT*1.002) GO TO 25

CALCULATE THE CHANGE OF MOLES IN RECEIVER TANK WITH VENTING.

DM <(H-H1)*FLOW1-Q-OWALL)/THETA

CHECK TO SEE IF THE SYSTEM IS VENTING PROPERLY.

IF ( ( DM-FLOWl ) .LT. 0.) GO TO 30

I F ( PRE S S .LT. P VENT*1 .002 ) GO TO 25

WR ITE ( 6 » 2 50 ) 250 FORMAT ( 1H ,*THE SYSTEM IS NOT VENTING PROPERLY)*,

* CONTACT A PROGRAMMER*)

NPLOT « NPL OT 1 X(NPLOT) TIME/60.

Y1 (NPLOT) » T49./5.-460.

Y2 ( NPLOT) PRESS*14.696

Y3 ( NPLOT ) FL0W1+MW*. 13216

YMNPLOT) M*MW/ 454.

Yf(NPLOT) - 0 . Y6 (NPL OT ) Y4(NPL0T)+Y5 (NPLOT)

Y7( NPLOT) - ETO

Y8 ( N°LOT ) TANKO

CALL P D AT A

(

M, XVFNT)

30 DPRESS 0.

PRESS • PVF NT FL0W2 • DM-FLOWl

SET FLAG TO SHOW THE RECEIVER TANK IS VENTING AND CALCULATE TOTAL

AMOUNT VENTED.

N VENT • 2 XVENT • XVENT-FL0W2+DTIME

GO TO 26

25 CONTINUE

26 DM FL0W1+FL0W2

CALCULATE NEW NUMBER OF MOLES PRESENT IN RECEIVER TANK.

M - M DM*DTIME

CHECK TO SEE IF ALL FLUID HAS BEEN TRANSFERRED.

I F ( M+ XV ENT .LT. 0.95*T0TAL)G0 TO *5

46 I F ( M + XV ENT .LE. TOT AL ) GO TO 48

47 M « M-D M*DT I ME 48 DTIME1 • (TOTAL-( XVENT+M) ) /DM

IF ( DTIME .LT. DTIME 1 ) GO TO 45

49 M M+DM*DTIME1

80
f»

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ooo

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c CALL

*5 CALL

UPDATE

DONE ( M* X VENT

)

CHECK ( HE T*PET*TET*ET 0)

THE SUPPLY TANK PROPERTIES

ETLIQ • T OT AL-M-X VE NT

CALL SUPPLY ( DTIME

)

IF BACK PRESSURE FROM RECEIVER TANK IN THE ABSENCE OF A PUMP STOPS

FLOW# CALL SUBROUTINE TO STOP PROGRAM.

IF (PRESS .GT. PET .AND. POWER .LT. ,05)G0 TO 33

33

23

*85

IF FLOW HAS STOPPED IN THE PRESENCE

FROM THE RECEIVER* CALL A SUBROUTINE

IF (ABS(FLOWl) .LT. .1) GO TO 3 GO TO 23

CONTINUE

NPLOT N PL OT 1 X(NPLOT) « TIME/60.

Yl(NPLOT) - T*9./5.-*60.

Y2 (NPLOT) PPESS+1A.696

Y3 ( NPLOT ) - FL0W1*MW*. 13216

Y* ( N°L OT ) M*MW/*5*.

Y5 (NPLOT) 0.

Y6(NPL0T) Y*(NPL0T)+Y5(NPL0T)

Y7 (NPLOT) • ETO

Y8 ( NPLOT) « TANKO

CALL PFAIL(

CONTINUE

M, X VFNT

)

I F ( DUM P .NE . 1 • ) GO TO *85

NPLOT NPL OT 1

X (NPLOT ) TIME/60.

Yl(NPLOT) • T*9./5.“*60.

Y2 (NPLOT) - PRESS*1*»696

Y3( NPLOT) - FL0W1*MW*. 13216

Y* (NPLOT) • M* MW /* 5* • Y?( NPLOT) 0.

Y6 (NPLOT ) • Y*(NPL0T)+Y5(NPL0T)

Y7 (

N

D L OT ) ETO

Y8 ( NPLOT ) - TANKO

CALL PD AT A

(

CONTINUE

M, X VE NT ) NPRT » NPRT 1

OF A PUMP DUE TO BACK PRESSURE

TO STOP PROGRAM.

WRITE SIMULATION VALUES INTO PLOT ARRAYS EVERY CHOSEN ITERATION.

IF (NPRT ,NE. 5) GO TO 35

N PR T • 0

K • 0

NPLOT N PL OT 1 X(NPLOT) - TIME/60.

Y1 (NPLOT ) - T*9./5.-*60.

Y 2 ( NPLOT ) P PE SS* 1 *» 69 6 Y3 (NPLOT ) PL0W1*MW*. 13216

YA(NPLOT) • M*M W/*5 *

Y5 ( NPLOT) « 0.

Y 6 (NPLOT) • YA(NPLOT)

Y7 ( NPLOT ) - ETQ

Y 8 ( NPLOT ) TANKQ

IF RECEIVER TANK TEMPERATURE IS GREATER

DON'T BOTHER CHECKING FOR TWO PHASES IN THAN CRITICAL TEMPERATURE*

RECEIVER TANK.

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I F (NGAS . E0,2 ) GO TO 19

35 IF (T .GE. 40.) GO TO 20

GO TO 36

19 IF(T.GE.157.)G0 TO 20

OBTAIN SATURATION TEMPERATURE AT RECEIVER TANK PRESSURE, USE THIS TO

GET SATURATION DENSITY} COMPARE SIMULATION AND SATURATION DENSITIES

TO DETERMINE WHETHER OR NOT ANY LIQUID IS PRESENT IN THE RECEIVER TANI

36 TSAT • FIND TV(PRESS)

TTPRES - PRESS-1. E-5

DS AT » FIND D ( TTPR E S, TS AT

)

DCALC M/VOL

IF (T .LT. TSAT) T • TSAT

IF (DCALC .LE. DS AT ) GO TO 20

IF TWO PHASES ARE PRESENT, BACK UP ONE ITERATION ANO RETURN TO THE

MAIN PROGRAM. SHUT OFF COOL-DOWN NOZZLES, RECALCULATE FLOWRATE.

M M - DM*DTIM£

DENS « DENS-DDENS

TIME TIME-DTIME

PRESS PRESS-DPRESS

T • FIND TV(PRESS)

CONST • 0.

C DL ENG 0. IJK - 1

F GUESS FL 0W1 * 5.

IF (NGAS .EQ. 2JFGUESS FGUESS*4.

FL0W1 • PUMPFLO(PRESS,FGUESS)

TIM « TIME/60.

WPITE(6,58)TIM,kqunT

58 F OR MAT ( /, * COOLDOWN TIME • *,F12.4,* K CUNT *,I6)

RETURN

20 I F (NPLOT .LE. 600)G0 TO 10

WRITE (6,151)

151 FORMAT(* ARRAY LENGTH EXCEEDED*)

CALL PDATA( M, XVENT)

END ************************************************************ *************

SUBROUTINE PPHI ( DD, TT, PHI I

)

SUBROUTINE TO CALCULATE THE GRUENSIAN PARAMETER < PHI I ) AS A FUNCTION OF DENSITY (GMOL/L) AND TEMPERATURE (DEG K).

D DD

T TT CALL DPDT(DT,D,T)

CAP • C V ( D, T

)

PH 1 1 DT/D/CAP*101.325

RETURN

END****** ************************************************ *************

FUNCTION TH(DENS, TEMP)

CALCULATE THE HEAT OF EXPULSION (J/GMOL) AS A FUNCTION OF

DENSITY (GMOL/L) AND TEMPERATURE (DEG K).

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CALL DPDT(DT, DENS, TEMP)

CALL DPDD(DD, DENS, TEMP)

TH CP (DENS,TEMP)*DENS*DD/DT

RETURN

END **************************************************************************

FUNCTION DVDP V ( PRESS)

COMMON/PROB/DUMP

CALCULATE THE PARTIAL DERIVATIVE OF SPECIFIC VOLUME WITH RESPECT TO

PRESSURE FOR A SATURATED VAPOR.

PVAP • PRESS-1. E-5

TEMP • FINDTV(PRESS)

V • l./FIND D ( PVAP# TEMP

)

SET AN INITIAL DELTA P

DP • .05

IF( (PRESS-DP) .LT. l.E-*)0P DP/2.

KOUNT 0 25 TEMP FIND TV(RRESS-DP)

VLOW • l./FIND D(PVAP-DP,TEMP)

TEMP - FIND TV(PRESS+DP)

VHICM • l./FIND D ( PV A P*DP , T EM P

)

DVDPV (VHIGH-VLPW) /DP/2.

SEE IF THE DERIVATIVE WILL CHANGE BY MAKING DELTA P SMALLER

IF (A5S((VHIGH-2.*V*VL0W)/(VHIGH-V)) .LT. l.E-3) RETURN

KOUNT KOUNT + 1

IF THE SOLUTION HAS NOT CONVERGED, MAKE DELTA P SMALLER.

DP DP /2.

IF THE DERIVATIVE HAS NOT CONVERGED IN 100 ITERATIONS, WRITE AN ERROR MESSAGE (THIS FUNCTION USUALLY CONVERGES WITHIN 2-3 ITERATIONS)

IF (KOUNT .LE. 100) GO TO 25

WRITE (6, 125)

125 FORMAT ( 1H , AMOUNT EXCEEDS 100 FOR DVDPV. STOP PROGRAM*)

DUMP • 1.

RETURN

END ****** ***t ******************************************************** ******* FUNCTION DVDPL (PRESS)

COMMON/PROB/DUMP

CALCULATE THE PARTIAL DERIVATIVE OF SPECIFIC VOLUME WITH RESPECT TO

PRESSURE FOR SATURATED LIQUID. INPUT IS PRESSURE (ATM), OUTPUT

DVDPL (L/GMOL/ATM)

PLIO - PR ES S + l • E-5

TEMP - FIND TV(PRESS)

V l./FIND D(PLIO,TEMP)

DP - .05

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IF( {PRESS-DP) .LT. l.E-4)DP - OP/2.

KOUNT • 0 25 TEMP - FIND TV(PPESS-DP)

VLOW • 1. /FIND D(PLIO-DP,TEMP)

TEMP FIND T V( PR E SS + DP

)

VHI6H « l./FIND D(PLIQ*DP,TEMP)

DVDPL ( VHIGH-VLOW) /DP/2.

SEE IF THE PARTIAL DERIVATIVE HAS CONVERGED.

IF (ABS( ( VHIGH-2.»V+VLOW) /( VHIGH-V) ) .LE. l.E-3) RETURN

KOUNT KOUNT+ 1

IF THE SOLUTION HAS NOT CONVERGED, MAKE DELTA P SMALLER.

DP DP / 2.

THE DERIVATIVE SHOULD CONVERGE IN 100 ITERATIONS (USUALLY,

2-3 ITERATIONS ARE SUFFICIENT).

IF (KOUNT .LE. 100) GO TO 25

VRITE(6,125)

125 FCRMATdH ,*KOUNT EXCEEDS 100 FOR DVDPL. STOP PROGRAM*)

DUMP . l.

RETURN

END ****** * ********* ******* *** 4 ******* ************************** ************** FUNCTION DUDPV(PRESS)

COMMON/PROB/DUMP

CALCULATE THE PARTIAL DERIVATIVE OF INTERNAL

TO PRESSURE FOR A SATURATED VAPOR. INPUT IS ENERC-Y WITH RESPECT

PRESSURE (ATM).

TEMP > FINDTV( PRESS)

DENS FIND D (PRE SS-1.E-5,TEMP)

SINCE INTERNAL ENERGY IS NOT RETURNED BY THE THERMODYNAMIC PROPERTIES

PACKAGE, U • H - PV

U • ENTHAL(PRESS-l.E-5, DENS, TEMP ) -PRE SS*101 . 327/DENS

DP - .05

IF( (PRESS-DP) .LT. 1.E-4JDP • DP/2.

KOUNT • 0

25 TEMP - FINDTV( PRESS-DP)

DENS « FIND D(PRESS-DP-1.E-5,TFMP)

ULOW ENTHAL (PRESS-DP-1. E-5, DENS, TEMP )-( PR ESS-DP ) *101 . 327/DENS

TEMP • FINDTV(PRE SS+DP)

DENS FIND D(PRESS^DP-1. E-5, TEMP)

UHIGH • ENTHAUPRFSS+ DP-l. E-5, DENS, TEMP )-( PRE S S + DP ) *101 .327/ D EN S DUDPV (UHIGH-ULOW) /DP/2.

SEE IF THE DERIVATIVE HAS CONVERGED.

IF(ABS( (UHIGH-2.*U*ULQV)/(UHIGH-U)).LT. l.E-3) RETURN

KOUNT • KOUNT 1

IF THE SOLUTION HAS NOT CONVERGED, MAKE DELTA P SMALLER.

DP DP /2.

IF (KOUNT .LE. 100) GO TO 25

WR ITE ( 6, 1 25 )

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125 FORMATdH ,*KOUNT EXCEEDS 100 FOR DUDPV. STOP PROGRAM*)

DUMP - 1. RETURN

END ******* *******   ** ** ******** ********************** ****** ****************

FUNCTION DUDP L (PRESS)

COMMON/ PROB/DUMP

CALCULATE THE PARTIAL DERIVATIVE OF INTERNAL ENERGY WITH RESPECT TO

PRESSURE FOR SATURATED LIOUID. INPUT IS PRESSURE (ATM)/ PARTIAL

DERIVATVE OUTPUT ( J /GMOL/ATM)

.

TEMP FINDTV( PRESS

)

DENS • FIND D(PRESS+1.E-5#TEMP)

U ENTHAL(PRESS+l.E-5#DENS#TEMP)-PRE$Sn01. 327/DENS

DP .05

I F C (PRESS-DP) • LT . 1 • E-A ) DP - DP/2.

KOUNT 0 25 TEMP FINDTV(PPESS-DP)

DENS FIND D(PRESS-DP*1.E-5»TEMP)

ULOV ENTHAL ( PRE SS-DP+1 . E-5# DE NS# TEMP )-( PRE SS-DP ) *101 . 327 /DENS

TEMP • FINDTV(PPESS*DP)

DENS • FIND D(PRESS*DP+1.E-5#TENP)

UHIGH ENTHAL ( PR F SS *DP *1. E-3 # DENS# TEMP)- (PR ESS *DP) *101.327/ DENS

DUO PL - (UHIGH-UL0W)/DP/2.

CHECK ACCURACY OF PARTIAL DERIVATIVE.

IF(ABS( (UHIGH-2.*U«-UL0V)/(UHIGH-U) > . LT. l.E-3) RETURN

KOUNT KOUNT 1

IF THE SOLUTION HAS NOT CONVERGED# MAKE DELTA P SMALLER.

DP « DP /2.

CHECK TO SEE IF THE SOLUTION IS CONVERGING (CONVERGENCE USUALLY

OCCURS IN 2-3 ITFPATIONS).

IF (KOUNT .LE. 100) GO TO 25

WR ITE ( 6 #125 ) 125 F OR MAT ( 1H #*KOUNT EXCEEDS 100 FOR DUDPL. STOP PR06RAM*

)

DUMP 1.

RETURN

END

*************************************************************************,

FUNCTION DTDP(PPESS)

C CALCULATE THE PARTIAL DERIVATIVE OF TEMPERTURE WITH

C RESPECT TO PRESS FOR A SATURATED LIOUID

C COMMON/PROB/DUMP

C TEMP - FINDTV(PRESS)

DP 0.05

I F ( PRE S S-DP .LT. 1 • E-4 )DP»DP/2.

KOUNT 0 25 THIGH - FINDTV(PRESS*DP)

TLOW • F I ND TV ( P RE SS-DP

)

DTDP - (THIGH- TLOWJ/DP/2.

C

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C CHECK CONVERGENCE

C IF(A8S( (THIGH-2. *TEMP*TL0W> /( THIGH-TEMP) ) .LE. l.E-3)

RETURN

KOUNT - KOUNT+1

REDUCE DP

DP DP/2.

IF (KOUNT .LE. 100) GO TO 25

WR I TE ( 6 , 125 ) 125 F OR HAT ( 1H ,*K0UNT EXCEEDS 100 FOR DTDP. STOP PROGRAM*

)

DUMP - 1. RETURN

END **************************************************************************

FUNCTION CWALL(TEMP)

CALCULATE THE HEAT CAPACITY OF THE TANK WALL (J/G/DEG K)

AS A FUNCTION OF TEMPERATURE (DEG K). WALL MATERIAL IS ALUMINUM

FOP LH2 AND INCONEL FOR LOX.

COMMON/PROP/NGAS

IF (NGAS.EQ.2) GO TO 1 C W ALL EXP (7. 29296-121. 912/TEMP*347.918/(TEMP**2))/1000.

GO TO 2

1 CWALL EXP(6. 462-106. 3/TEMP+321.9/(TENP**2))/1000.

2 RETURN

END **************************************************************************

FUNCTION FLO(PRESS)

CALCULATE THE PUMPLESS FLOWRATE (GMOL/SEC) AS A FUNCTION OF

SUPPLY AND RECEIVER TANK PRESSURES (ATM). FOR THIS FUNCTION* THE

SUPPLY TANK PRESSURE MUST BE GREATER THAN THE RECEIVER TANK PRESSURE.

COMM ON /FLOW/ DIAM,DET,TET, PET, LENGTH, PME TER COMMON/NOZZLE/CDIAM,NOZDIA,HEADIA,NNC7,CONST,CDLENG

COMM nN /PAR AM/ M W, M W AL L , 0, V OL , OP I P E, 0 E T, TOT AL , P VENT

C0*»M0N/PR09/DUHP

PEAL LENGTH, MW, MWALL,NOZDIA

PI - 3.14159

INITIALIZE THE FRICTION FACTOR.

FLINE • 0.005

FCOOL 0.005

PMETER • (PET-PRESS)*0.05

KOUNT • 0 CALCULATE FLOWRATE, OBTAIN A NEW FANNING FRICTION FACTOR, THEN

RE-CALCULATE THE FLOWRATE. THIS CONTINUES UNTIL THE FRICTION

FACTOR CHANGES SIGNIFICANTLY

35 CONTINUE

CALCULATE CONSTANTS FOR INDIVIDUAL PRESSURE DROPS

MAIN TRANSFER LINE

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c CLINE • (3.1561?*MV*LENGTH)/(DET*PI**2*DIAM**5)

COOLDOWN LINE

CCOOL (3. 15B15*MW*CDLENG) / ( DE T*P I **2*CD I AM** 5

)

COOLDOWN NOZZLES

A CONST * 6.7162E-2 / (NOZDIA**2)

B 1.9A1E-3 * MW / DET

C • 1. - ( ( NOZDIA/HEADI A) ***> CNOZ ( ( A**2 ) * B * C ) / FLOAT(NNOZ) * 4.725E-*

CALCULATE FLOWRATE

FLO $ QR T( (PET-PR ESS-PME TE R )/(CLINE*FLINE+CCOOL*FCOOL*CNOZ))

CALCULATE NEW FRICTION FACTORS

FLNEW FRICT(FLO*TET,DET#DIAM)

F C NEW - FRICT(FLO,TET*DET,CDIAM)

CONVERGENCE CHECK

IF(ABS(FL NE W-FLI NE )/FLINE.LT.O. Cl. AND. ABS(FCNEW-FCOOL)/ FCOOL

.LT.O.ODGO TO 80

GO TO 81

80 CONTINUE

. WRITE (6*77) FL INE*FCOOL

77 FO RM AT ( * FLINE • *>E12.5,* FCOOL **E12.5)

R ETURN

81 CONTINUE

ITERATE

FLINE FLNEW

FCOOL FCNEW

KOUNT • KOUNT+1

I F (KOUNT « L T. 100)G0 TO 35

WP ITE ( 6* 1 00 ) 100 FpRfAT ( 1H * KOUNT EXCEEDS 100 FOR FLO. STOP PROGRAM*)

101 DUMP . i,

RETURN

END

FUNCTION FRICT(FLO*T*D*DIAM)

CALCULATE THE FRICTION FACTOR AS A FUNCTION OF PIPE ROUGHNESS AND

REYNOLDS NUMBER.

COMM ON /PAR AM/ MW*MWALL»0,VOL»OPIPE»QET*TOTAL»PVENT

COMMON/PROP/NGAS

REAL MW#MWALL

PI « 3.1*159

CALCULATE THE DIMENSIONLESS REYNOLDS NUMBER

IF ( NGAS .E0.2 ) GO TO 1 REY - *.*FL0*MW/(1.8367E-**DIAM*PI)

GO TO 2

1 REY - *.*FLO*MW/< V I SC ( D* T ) *1 . E-6* D I AM* P I

)

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C THE PIPE ROUGHNESS IS ASSUMED TO BE 0.00015 INCHES

C 2 EPSILON » . 00015*30. *8

FRICT • (-4. *AL0G10(EPSIL0N/DIAM/3. 7-5. C2/REY*AL0G10( EPSILON

/DIAM/3.7 14.5/REY)) )**(-2

)

RETURN

END

************************+*****************»*******«************************>

SUBROUTINE CHEC K ( HI, PRESS > TEN P, OUAL

)

CHECK THE OUAL I T Y OF A STREAM OP TANK GIVEN ENTHALPY (J/GHOL),

PRESSURE (ATM) AND TEMPERATURE (DEG K).

TSAT FIND TV(PRESS)

DS AT • FIND D(PPESS*1.E-5,TSAT)

HCALC ENTHAL(PRESS+1.E-5,DSAT,TSAT)

IF (HCALC .LT. HI) GO TO 10

IF ACTUAL ENTHALPY IS LESS THAN LIOUID SATURATION ENTHALPY# THE LIQUID IS SUBCOOLED AND THERE IS NO VAPOR PRESENT (OUAL • 0).

OUAL 0.

R FTURN

10 D V A P - FIND D(PRESS-1.E-5,T$AT)

HVAP • ENTHAL(PRES$-1.E-5»DVAP,TSAT)

CALCULATE THE QUALITY USING ACTUAL, LIOUID ANO VAPOR ENTHALPIES.

OUAL -100.+ (HCALC -HI)/ (HCALC-HVAP)

P ETURN

END

**** ********** *************************************************************

FUNCTION PUM°FL0(PRESS,PFL01)

CALCULATE THE FLOWRATE BETWEEN TANKS (GMOL/SEC) IN THE PRESENCE OF

A PUMP (J/S). THIS ROUTINE REQUIRES AN INITIAL GUESS FOR THE FLOWRATE

.

COMM ON /FLOW/ DIAM,DET,TET, PET, LENGTH, PMETER

COMMON/NOZZLE/CDIAM,NOZDIA,HEADIA,NNOZ,CONST,CDLENG

COMM ON /PAR AM/ M W, M WA L L , 0, VOL , OP I P E , GET , TOTAL , P VENT

CPMHON/PUMP/ POWER, EFF COMMON/PROB/DUMP

COMHON/NEC-/IJK

REAL MW, MWALL, LENGTH, NOZDIA

KOUNT 0 DP PET-PRESS

PMETER • DP *0 ,05

PI 3.14159

25 EFF PEFF(PFLOl)

CALCULATE A THEORETICAL PRESSURE DROP (OP RISE) BETWEEN TANKS.

NOZZLE PRESSURE DROP

A • CONST * 6.7162E-2 / (N0ZDIA**2)

B 1.941E-3 * MW / DET

C • 1. - ( (NOZDIA/HE ADIA)**4)

DPN07 (

( P FL 01**2 ) * < A * *2 ) * B * C) / FLOAT (NNOZ) 4.725E-4

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PCOOL FRICT(PFL01#TET»DET#CDIAM)

0 PC 00L« (PFL01#*2)*(3.15815*Mw#CDLENG*FCCCL)/(DET*PI**2*CDIAM**5)

MAIN TRANSFER LINE

FLINE FRICT(PFLC1»TET,DET#DIAM)

PPLINE • (PFL01*P2)*(3.15815*MW*LENGTH*FLINE)/(DET*PI**2*DIAM#*5)

PUMP

DPPUMP • (O.OO9068*POWEP*EFF*DET) /{ PFL01)

CALCULATE PRESSURE DROP

DPCALC1 • PMETER DPNOZ DPCOOL DPLINE - DPPUMP

INCREMENT FOP INTER ATION

KOUNT - KOUNT 1 IF (KOUNT .GT. 1) GO TO 10

PFLO • PFL01

PFL01 • P FL 01 *1 •

5

DPCALC • DPCALC1

GO TO 2“

CALCULATE A NEW FLOWRATE USING A OUASI-NEWTON METHOD.

NOMENCLATURE « PUMPFLO - FLOWRATE (GMHL/S) AT N*1 ITERATION

PFLOl - FLOWARATE AT N ITERATION

PFLO - FLOWATE AT N-l ITERATION

DPCALC1 - CALCULATED PRESSURE DROP (ATM) AT N ITERATION

DPCALC - CALCULATED PRESSURE DROP AT N-l ITERATION

DP - ACTUAL PRESSURE DRO° (OR RISE) BETWEEN TANKS.

10 PUMPFLO • PFL01-(DP-DPCALC1)*(PFL01-PFL0)/(DPCALC-DPCALC1)

CHECK TO SEE IF THE THEOPETICAL AND ACTUAL TANK PRESSURE

DIFFERENCES ARE WITHIN 0.01? OF EACH OTHER.

CONVERGENCE CHECK

I F ( ASS ( (DPC ALC1-DP) /DP) .LT. l.E-4) GO TO 180

GO TO 170

180 CONTINUE

160 CONTINUE

RETURN

170 CONTINUE

ITERATE THE FLOWRATE# CALCULATE PRESSURE DROP.

DPCALC DPCALC1

PFLO - PFLOl

PFLOl PUMPFLO

IF (KOUNT .LT. 100) GO TO 25

WR ITE ( 6# 1 00 ) 100 FORMAT ( 1H # *K OUNT EXCEEDS 100 FOR PUMPFLO. STOP PROGRAM#

)

DUMP - l,

RETURN

END

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o **************** ****** ******* * * ** * * ******** ** *** * *** * ******** ************ *, FUNCTION PEFF(FLOWl)

CALCULATE PUMP EFFICIENCY OF A CENTAUR PUMP

COMM ON /FLOW/ DI AM, DET, TET, PET, L ENGTH, PMFTE

R

common/prop/ngas

REAL LENGTH

CHANGE UNITS ON FLOWRATE FROM GMOL/S TO GALLONS/MIN.

G PM FL0W1*15.8502/DET

CALCULATE PUMP EFFICIENCY

IF(NGAS.EQ.2> GO TO 1 PEFF«(.39213*.09662*GPM*2.7797E-5*(GPM**2)-

8.1723 E-e*(GPM**3) *2. 5008 E-ll* ( GPM**4 ) )/100.

GO TO 2

1 PEFF (. 32031*. 48261*GPM-1.6223E-3*<GPM+*2)+

3.9836E-6*(GPM**3)-4.8853E-9*{GPM+*4) )/100.

2 CONTINUE

R ETURN

END ***************************************************************************

SUBROUTINE PF AI L( M, XVENT)

THIS SUBROUTINE FINISHES OFF THE PROGRAM. PFAIL IS USED WHEN

FLOW BETWEEN TANKS STOPS DUE TO BACK PRESSURE FROM THE RECEIVER

TANK.

COMMON /SUB/ F L OW 1, F L OW 2, PRESS, TEMP, TIME, HET

COMM ON /PAR AM/ MW, NWALL , 0, VOL , OP I PE , QET, TOTAL , P VENT

COMMON /FLOW/ D I AM , DE T, T E T, P E T, L E N GTH , PME TE

R

COMMON /PLOT/ NPLOT, X,Y1, Y2,Y3, Y4, Y5,Y6,Y7,Y8

COMMON/PROP/NGAS

DIMENSION OPLOT(ie)

REAL X(600),Y1(600),Y2(600) , Y3 < 600 ) » Y4 ( 600 > , Y5 { 600 ) » Y6 < 600

)

, Y7(600),Y8(600)

REAL M, MW, HWALL, LENGTH

CONVERT TIME FROM SECONDS TO MINUTES, PRESSURE FROM ATM TO PSI#

TEMPERATURE FROM DEG K TO DEG F AND QUANTITY FROM GMOL TO LB.

XTIME TIME/60.

X PRESS • PR E S S* 14 • 696

PET PET*14. 696

XTEMP TEMP*9./5.-460.

TET TET*9./5.-460.

XM • M* MW /4 54 • X OUT XVENT*MW/454.

WRITE A MESSAGE STATING WHY THE SIMULATION STOPPED AND WHAT THE CONDITIONS WERE AT THAT TIME.

WRITE (6, 100) XTIME, XTEMP, XPRESS,XM, XOUT

100 FORMAT!//* AT *,F7.3,* MINUTES FROM START OF PROPELLANT*

,* TRANSFER*/,* FLOW HAS STOPPED DUE TO BACK PRESSURE FROM*

,* THE RECEIVER TANK .*,//, AT THIS TIME THE RECEIVER TANK*,

* IS AT *, F7.2,* DEG F, *,F7.2,* PSIA*/,

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AND CONTAINS *#F10.2#* POUNDS *#

//#* DURING THE SIMULATION *#F8.2#* POUNDS WERE VENTET*)

C WRITE!6#101)TET#PET

101 FORMAT! /* SUPPLY TANK IS AT *F9.4#* DEG F# *F7.2 #* PSIA*)

SKIP OVER OTHER MESSAGES AND GO TO INITIALIZATION OF PLOT DATA

AND PARAMETERS.

GO TO 10

ENTRY FULL

THIS ENTRY IS USED WHEN THE RECEIVER TANK IS FULL OF LIOUID.

CONVERT TIME # TEMPERATURE# PRESSURE AND OUANTITY IN RECEIVER TANK TO

ENGLISH UNITS.

I F { M .LT. TOTAL .AND. X VE NT .EO. 0.)M - TOTAL

I F ( M+XVENT .NE. TOTAL ) M TOT AL-X VENT

XTIME TIMF/60.

XTEMR TEMP*9./5.-460.

TET • TET+9./5.-460.

XRRESS • PR ES S* 14 • 696

PET - PET*14.696

XM • M*MW/454.

XOUT XVENT*MW/454.

WRITE OUT A MESSAGE STATING WHY THE SIMULATION STOPPED AND WHAT THE

CONDITIONS WERE AT THAT TINE.

WRITE (6 #110) XTIME# XTEMP, XPRESS# XM# XOUT

110 FORMAT!//#* AT *#F7.3#* MINUTES FROM START OF PROPELLANT*#

* TRANSFEP#*/#* THE RECEIVER TANK IS FULL.*//#* AT THIS TIME * *THE RECEIVER TANK IS AT *#F7.2>* DEG F, *#F7.2#* PSIA,*/#

* AND CONTAINS # F10.2#*P0UNDS*#

//#* DURING THE SIMULATION *,F8.2#* POUNDS WERE VENTED*)

WRITE!6#111 )TET#PET

111 FORMAT!/* SUPPLY TANK IS AT *F9.*#* DEG F# *F7.2#* PSIA*)

SKIP OVER UNWANTED MESSAGE.

GO TO 10

ENTRY DONE

THIS ENTRY IS USED WHEN THE SUPPLY TANK IS EMPTY.

I F ( M .LT. TOTAL .AND. XVENT .EO. 0.)M TOTAL

I F C M*XVENT .NE. TOT AL ) M « TOT AL-XVENT

CONVERT TO ENGLISH UNITS.

XTIME « TIME/60.

XTEMP TEMP*9./5.-*60.

TET - TET*9./5.-A60.

XPRESS • PRESS*1A. 696

PET P ET*1 4 • 696

XM M* MW/4 54.

XOUT XVEN T* MW /454

WRITE AN APP ROPR I ATE

WR][ TE 1

6

#120 ) XT IME#

FORMAT! /#* AT * #F7.

* TRAN SFER /#* THE

+ * RECE IVER TANK IS

* AND CONTAINS * # F

CONDITIONS.

OF PROPELLANT*#

#/#* AT THIS TIME THE*

F7.2# PSIA,*/#

91
noon

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r>

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no

o

/,* DURING THE SIMULATION *,F8.2,

* POUNDS WERE VENTED*)

C WPITE(6,121)TET,PFT

121 FORMAT! /* SUPPLY TANK IS AT *F9.4>* DEG F, *F7.2,* PSIA*)

C IDENTIFY THE PROPELLANT FOR THE PLOTTING ROUTINE.

C GO TO 1C

ENTRY PDATA

THIS ENTRY IS USED WHEN A PR06R ANMED STOP IS EXECUTED

CONVERT TO ENGLISH UNITS

XTIME TINE/60.

XPRESS • PR ESS*14 .696

PET • PET*14.696

XTEMP - TEMP*9./5.-460.

TET - TET*9./5.-460.

XM - n*hv/454.

X OUT • XVENT*NW/454.

WRITE A MESSAGE STATING THE CONDITIONS WHEN PROGRAM IS STOPPED

WRITE (6, 140) XTIME, XTE HP, XPR ESS, XM.XOUT

140 FORMAT!//,* AT *,F7.3,* MINUTES FROM START OF PROPELLANT*,

* TRANSFER*/,* A STOP IS REACHEO*, //* AT THIS TIME THE*

* RECEIVER TANK IS AT *,F7.2,* DEG F, *,F7.2,* PSIA,*/,

* AND CONTAINS , F 10. 2 , * POUNDS *,

//,* DURING THE SIMULATION *,F8.2,

* POUNDS WERE VENTED*)

WRITE! 6,141 )TET, PET

141 FORMAT!//* SUPPLY TANK IS AT *F9.4,* DEG F, *F7.2,* PSIA*)

10 CONTINUE

IF(NGAS.E0.2)G0 TO 11

WP ITE ! 8,190 ) 190 FORMAT! *HYDROGEN*)

GO TO 12

11 WP ITE i B ,191

)

191 FORMAT! *OXYGEN*)

12 CONTINUE

WRITE THE NUMBER OF PLOT POINTS FOR USE BY THE PLOT ROUTINE.

WP ITE ! 8, 200 ) NPLOT

200 FORMAT ( 13 )

OPL OT (4 ) ARE BOUNDS FOR Yl, 0PL0T<5) AND OPLOT(6) ARE BOUNDS

SET LOWER AND UPPER BOUNDARIES FOR PLOTS

0PL0T11) 0.

0PL0T12) 0. DO 708 1-1,4

I F ( TIME /60. .LE. 10.)0t>L0T(2) - 10.

IF(TTME/60. .LE. 5.)0PL0T(2) • 5.

IF (TIME/60. .GT. OPL OT (2 ) ) OP LOT ( 2 ) 0PL0T(2) 50.

708 CONTINUE

0 PL OT ( 3 ) - -500.

IF(NGAS.E0.2)OPLOT(3) -400.

OPLOT

(

4 ) 0. IF(NGAS.EQ.2)0PL0T(4) 100.

DO 55 J 1,3

92
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n

IF(Y1(1) .GT. OPLOT(A)) OPLOTU) DPLOT (4 )+100«

55 CONTINUE

0 PL OT ( 5 ) 0.

OPLOT(6) 50.

00 57 I-1,NPL0T

I F { (Y2( I).GT.0PL0T(6) ) . AND. ( Y2 ( I ) . LT . < 0PIDT(6 ) +50 . ) )) OP LOT (6)

OPLOT(fe) 50.

57 CONTINUE

56 OPLOT( 7 ) 0.

OPLOT ( 8 ) • 2000.

IF(NGAS.E0.2)0PL0T(8) 10000.

OPLOT( 9 ) • 0.

OPLOT( 10) • 250.

TOTAL • TOT AL / A54 • *MW

DO 1000 1-5000,65000,5000

IF( TOTAL. LE.FLOAT(I))OPLOT( 10) • F LOAT ( I ) *0 . 10

IF(TOTAL.LE.FLOAT(I))GO TO 1001

1000 CONTINUE

1001 CONTINUE

OPLOT(ll)

OPL 0T( 1 2 ) OPL OT ( 1 3

)

0PL0T(14)

0 PL OT ( 1 5 ) OPL 0T{ 1 6)

OPLOT (17)

0 PL OT ( 1 8

)

0.

OPLOT ( 10)*10.

0.

OPLOT ( 12

)

0 . ICO.

0 . 100 . WRITE PLOT PARAMETERS FOR PLOTTING ROUTINE.

WRITE(6,*) (OPLOT (II), I 1-1,18)

WR I TE(8»*)(0PL0T(II), 11-1,18)

WRITE ARRAYS CONTAINING SIMULATION VARIABLES.

WRITE (6,249) ( X(I), Y1 (I ), 1-1,2

)

2*9 FORMAT( 2F15.5

)

WRITE (8,250) ( X ( I ) , Y1 (I) , Y2 ( I ) , Y3 ( I ) , Y* ( I ) , Y5 ( I ) , Y6 ( I ) , Y 7 ( I), Y 8 ( I ), I»1,NPL0T)

250 FORMAT(F8.3,T10,F8.3,T20,F8.5,T30,F8.2,T*0,F8.1,T50,Fe.l,T60,F8.1

>T7O,F8.3,T0O,F8.3)

STOP

ENP

*************************************************************************,

SUBROUTINE SUPPL Y( DTIME

)

COMMON /SUB / FLO W1,FL0W2, PR ESS, TEMP, TIME, MET

COMMON /FLOW/ DIAM,DET,TET, PET, LENGTH, PME TER

COMMON /PAR AM/ MW , M W A LL , Q , VOL , OP I P E , 0 ET , TOT A L , P VEN

T

COMMON/PROB/DUMP

COMMON /ETANK/ETLIO,ETVAP, VET, ETO

REAL MW, MWALL, LENGTH

THIS SUBROUTINE MONITORS THE PROPERTIES OF THE SUPPLY TANK.

INITIALIZE THE SUBROUTINE

ENTHALPY AND HEAT CAPACITY OF LIOUID IN SUPPLY TANK.

HL - HET

CSUBP • CP(DET,TET)

C

C FRACTION OF TANK VOLUME OCCUPIED BY LIOUID AND AMOUNT OF

C HEAT TO EACH PHASE.

93
non

non

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o

FP ACT ETLIO/VET/DET

DOL OET+FRACT

00V • OET-DOL

SPECIFIC VOLUME OF LIOUIO . VFTIIQ l./DET

SATURATION TEMP AT GIVEN PRESSURE » AND THE VAPOR DENSITY.

TETSAT FINDTV(PET)

DETVAP - FINDD(PET#TETSAT+l.E-3)

SPECIFIC VOLUME OF VAPOR.

VETVAP 1. /DETVAP

GRUNEISEN PARAMETER FOR VAPOR AND LIQUID.

CALL PPHI(DETVAP#TETSAT*1.E-3#PHII)

GRUVAP - PH 1

1

CALL PPHI (DET#TET» PHII

)

GRULIQ PHII

HEAT OF EXPULSION FOR VAPOR AND LIOUID

THETAV TH(DETVAP,TETSAT+l.E-3)

THETAL - TH ( DE T# T ET ) CALCULATE THE CHANGE IN THE SUPPLY TANK PRESS WITH TIME

DPET - ((-FL0W1*VETVAP/VFTLIQ/THETAV*D0V*1./THETAL

1 *D0L) /ETLIO/ ( VETLIO/THETAL/GRULIO+ETVAP*

2 VETVAP **2/ETLIQ/VETL IQ/THETA V/GR UVAP ) /101.327)*DTIME

CALCULATE THE CHANGE IN THE SUPPLY TANK LIOUID TEMPERATURE

WITH TIME

DTET • ( (DOL/ETLIQ*VETLIQ*ALPHAL ( PE T# TE T# DE T ) * D PE T*1 01 . 327

1 /DTIME )/CSU«P)*DTIME

CALCULATE THE CHANGE IN THE SUPPLY TANK LIQUID ENTHALPY WITH

TIME

DHL - (DOL/ETLI0+VETLIQ*DPET/DTIME*101.327)*DTIME

INCREMENT THE PRESSURE# LIQUID TEMPERATURE AND ENTHALPY

PET PET+DPET

TET - TET+DTET

HL HL+DHL

OBTAIN NEW LIOUID DENSITY AND ENTHALPY FROM FLUIDSPACK

OBTAIN THE SUPPLY TANK LIQUID QUALITY

501 DET • FINDD(PET»TET)

HET ENTHAL( PET#DET#TET>

CALL CHECK (HET# PET# TET»ETO)

IF OUALITY IS GREATER THAN 7ER0# CAVITATION COULD OCCUR. STOP

TRANSFER IMMEDIATELY.

IF( ETQ.LT.l .E-6JG0 TO 99

WR ITF (6# 225 ) ETO

94
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225 F OR MA T ( 1H0, *E T LIO BOILING. STOP TRANSFER*, 5X, *ETO « *E12.5)

DUMP 1. RETURN

COMPARE MODEL AND fluidspack ENTHALPIES. IF THE VALUES ARE WIDELY

DISPARATE, the et model is in error, stop the program.

OTHERWISE USE THE MODEL VALUE.

99 IF(ABS< (HET-HD/HL) .GT. 0.100)G0 TO 100

HET HL RETURN

IOC WRITE(6,255 )HET,HL

255 FORMAT! 1H0, * ENTHALPY DISPARITY. HET - *E12.5,* HL *E12.5)

DUMP 1.

RETURN

END

FUNCTION ALPHAL(PET,TET,DET>

COMMON/ PROB /DUMP

THIS FUNCTION CALCULATE THE BULK EXPANSIVITY FOR THE LIQUID

SET THE TEMPERATURE STEP AND THE LOOP COUNTER

DT 0.05

KOUNT - 0 FIND VALUES SLIGHTLY ABOVE AND BELOW THE ACTUAL TEMPERATURE

FOR THE DENSITY

25 DHIC-W « FINDD(PET,TET-DT)

DLOW • FINDD! PE T, TE T + DT ) CALCULATE THE BULK EXPANSIVITY

ALPHAL -TET/DET*(DHIGH-DL0W)/DT/2.

IF(A«S{ (DHIGH-2.*DET+DLQW)/ (DHIGH-DET) ) .LT. l.E-3)RETURN

KOUNT » KOUNT 1

IF THE VALUES ARE NOT CONVERGING, MAKE THE TEMPERATURE STEP SMALLER

DT DT/2.

IF ( KOUNT. LE .100) GO TO 25

WR ITE (6,125

)

125 FORMAT (1H1,*K0UNT EXCEEDS 100 FOR ALPHAL. STOP PROGRAM*)

DUMP « 1.

RETURN

END

95
DEMO

.PROC ,DEMO.

.*

.* DEMONSTRATION PROGRAM USING DISSPLA 9.0.

EVICT, LGO, PLOT.

FTN,I=PROG ,L=FAIL,R=3 ,PMD.

IFE, FILE (GRAF ING , . NOT. AS) , JO.

G ET , GRAF ING /U N=G RAF

.

ENDIF , JO

.

GET,TAPE2=P5DATA.

BEGIN,DISPLA9 ,GRAFING

.

RETURN, PROG, LGO.

REPLACE, PLOT.

RENAME, Z=P LOT.

SKIPR,Z

.

CO PYBR,Z, OUTPUT, 1

.

REVERT.

EXIT.

REVERT, ABORT.

REPLACE, FAIL.

•DATA, PROG

PROGRAM DEMO ( INPUT, TAPE2 ,0UTPUT=/1000 ,PL0T=/1000

)

REAL LMIN,LMAX

DIMENSION X(400) ,Y1(400) ,Y2(400) ,Y3(400) ,Y4(400) ,Y5(400 ) , + Y6(400) ,Y7(400) ,Y8(400)

DIMENSION XAXIS (4 )

, HEAD ( 3 ), IPKRAY ( 300 ) ,L1(3) ,L2( 3 ) ,L3 ( 3 ) ,L4 (3

)

DIMENSION NAME(2) ,IPK2(100)

DATA XAXIS /10HTIME (MINU, 10HTES)$ ,2*10H

READ (2,*) DIAM, POWER, TEMP, PRESS

READ (2 , 80) NAME ( I ), NAME ( 2

)

80 FORMAT ( 2 A4)

READ(2 ,*) N

READ ( 2

, * ) TMl , TM2 , TMIN , TMAX , PMIN , PMAX , FMIN , FMAX , VMIN

,

+ VMAX , LMI N , LMAX , DUM1 , D UM2 , DUM3 , DUM4 , DUM5 , DUM6

DTIME = (TM2-TM1 ) /10

.

DTEMP = (TMAX-TMIN) /5

.

DPRESS = (PMAX-PMIN) /5

.

DFLOW = (FMAX-FMIN) /5

.

DVAP = ( VMAX-VMIN ) / 5

.

DLIQ = (LMAX-LMIN) / 5

.

DO 10 1=1,

N

10 READ (2 ,*) X(I),Y1(I),Y2(I),Y3(I),Y4(I),Y5(I),Y6(I),Y7(I),Y8(I)

CALLID( " LOUIE, $’’,100)

C CALL HP7221

CALL FR80(0 .0

)

C CALL TK4010( 120)

C CALL HWSPEC (4HPL0T, 4HFILE)

CALL NOBRDR

CALL PHYSOR( 1.25,6.)

CALL AREA2D(6. ,4.)

ENC0DE(30, 100, HEAD) NAME(1 ) ,NAME(2

)

96
100 F0RMAT(2A4," PROPELLANT TRANSFER? ")

CALL HEADIN(HEAD, 100, 1.25,1)

CALL XNAME(XAXIS.IOO)

CALL YNAME( "TEMPERATURE (DEG F)$”,100)

CALL YAXANG(0 .

)

ENCODE (30 ,15 ,L1 ) DIAM

15 FORMAT( "DIAMETER: ",F4.1," IN.$")

ENCODE (30 , 20 ,L2 ) POWER

20 FORMAT ("PUMP: ",F4.1," HP$")

ENCODE (30

,

25 ,L3 ) TEMP

25 FORMAT ("TANK TEMP: ",F6.1," DEG F$")

ENCODE (30 ,30 ,L4) PRESS

30 FORMAT

(

"TANK PRESS: ",F4.1," PSIA$")

CALL LINES (Ll , IPKRAY , 1

)

CALL LINES(L2 , IPKRAY , 2

)

CALL LINES(L3, IPKRAY, 3)

CALL LINES(L4, IPKRAY, 4)

CALL LSTORY ( IPKRAY , 4 ,

3

. 5 , 3 . 0

)

CALL GRAF( TM1 ,DTIME , TM2 , TMIN , DTEMP , TMAX)

CALL CURVE(X,Y1,N,0)

CALL ENDGR(O)

CALL PHYS0R(1 .25,1.)

CALL AREA2D(6. ,4.)

CALL XNAME(XAXIS ,100)

CALL YNAME( "PRESSURE (PSIA)$ " , 100

)

CALL YAXANG (0 .

)

CALL GRAF(TM1 ,DTIIiE ,TM2 ,PMIN,DPRESS , PMAX)

CALL CURVE (X ,Y2 ,N, 0)

CALL ENDGR(O)

CALL ENDPL(O)

CALL NOBRDR

CALL YAXANG (0 .

)

CALL PHYS0R(1 .25,6.)

CALL AREA2D(6. ,4.)

CALL HEADIN(HEAD ,100,1.25,2)

CALL HEADIN( "(PAGE 2 ) $

"

, 100 , 1 . ,2

)

CALL XNAME ( XAXI S , 1 00

)

CALL YNAME( "POUNDS IN VAPOR PHASE? ”,100)

CALL GRAF(TM1 ,DTIME,TM2 , VMIN.DVAP , VMAX)

CALL CURVE (X,Y4,N,0)

CALL ENDGR(O)

CALL YAXANG(0 .

)

CALL PHYSOR( 1.25,1.)

CALL AREA2D (6 • ,4 .

)

CALL XNAME (XAXIS,100)

CALL YNAME ("POUNDS IN LIQUID PHASE? ”,100)

CALL GRAF(TM1 ,DTIME,TM2 ,LMIN ,DLIQ ,LMAX)

CALL CURVE(X,Y5,N,0)

CALL ENDGR(O)

CALL ENDPL(O)

CALL NOBRDR

CALL YAXANG (0 . ) CALL PHYS0R( 1.25,6.)

CALL AREA2D (6 . ,4.)

97
CALL HEADIN(HEAD ,100,1.25,2)

CALL HEAD IN( "(PAGE 3)$ " , 100 , 1 . , 2

)

CALL XNAME(XAXIS ,100)

CALL YNAME( "TOTAL POUNDS TRANS F ERRED $”, 100)

CALL GRAF(TM1 ,DTIME ,TM2 ,LMIN ,DLIQ ,LMAX)

CALL CURVE (X,Y6 , N,0)

CALL ENDGR(O)

CALL YAXANG(0 .

)

CALL PHYSOR( 1.25,1.)

CALL AREA2D(6. ,4.)

CALL XNAME (XAXIS,100)

CALL YNAME ("FLOWRATE (POUNDS/MIN)$ "

, 100)

CALL GRAF(TM1 ,DTIME,TM2 ,FMIN,DFLOW,FMAX)

CALL CURVE (X,Y3 , N,0)

CALL END PL (0)

CALL PHYSOR( 1.5,6.)

CALL AREA2D(6. ,4.)

CALL HEADIN(HEAD ,100,1.25,2)

CALL HEADIN( " (PAGE 4)$" ,100 , 1 . ,2)

CALL XNAME(XAXIS , 100

)

CALL YNAME (1H ,1)

CALL YNONUM

CALL LINES( "SUPPLY$ "

, IPK2 , 1

)

CALL LINES( "RECEIVER INLET$ " , IPK2 ,2

)

CALL GRAF(TM1,DTIME,TM2,-10. ,120. ,110.)

CALL RLVEC(TMl-.2 ,0. ,TMl+.2 ,0. ,0)

CALL RLVEC(TMl-.2 ,100. ,TM1+.2,100. ,0)

XI = XINVRS (XMESS( "100% LIQ. $",100),0.)

X2 = XINVRS(XMESS( "100% VAP. $",100),0.)

CALL RLMESS( "100% LIQ. $

"

, 100 ,TM1- .2-X1 ,0 .

)

CALL RLMESS( ”100% VAP. $" , 100 ,TMl-.2-X2 , 100 .

)

CALL CURVE (X ,Y7 ,N , 10)

CALL CURVE (X ,Y8 ,N, 10)

CALL LEGEND ( IPK2 ,2,3. , 3 .

)

CALL ENDPL(O)

CALL DONEPL

STOP

END

98
FPLOT

PROGRAM PLOT ( INPUT, TAPE6 ,OUTPUT=TAPE6 , TAPE8=INPUT)

REAL TIME(400) ,TEMP(400) ,PRESS(400) ,FLOW1(400) ,MVAP(400) ,MLIQ(400)

REAL LLB ,LUB

READ (8 ,*) DUM1 ,DUM2 ,DUM3 ,DUM4

READ(8 ,90) NAME

90 FORMAT (A10)

READ(8 , 100) N

100 F0RMAT(I3)

READ ( 8

, * ) TLB , TUB , TEMPLB , TEMPUB , PLB , PUB , FLB , FUB , VLB , VUB , LLB , LUB

,

+ TOTLB ,TOTUB ,Q1LB ,Q1UB ,Q2LB ,Q2UB

DO 10 I = 1,N

10 READ(8 ,110) TIME (I) ,TEMP(I) ,PRESS(I) ,FL0W1 (I) ,MVAP(I) ,MLIQ(I)

110 FORMAT (F8 .3 ,T10 ,F8 . 3 ,T20 ,F8 . 5 ,T30 ,F8 . 2 ,T40 ,F8.1,T50,F8.1)

ILOG = 0

ISIZE = 0

NOUT = 0

WRITE(6 , 120

)

120 FORMAT( 1H1 , *ORBITER TANK TEMPERATURE (DEGREES F) VS.*

+ ,* TIME (MINUTES)*)

CALL PPC(TEMP ,TIME ,N, ILOG , ISIZE , NOUT , TEMPLB , TEMPUB , TLB , TUB)

WRITE(6 ,130)

130 FORMAT ( 1H1 ,*TANK PRESSURE (PSIA) VS. TIME (MINUTES)*)

CALL PPC(PRESS, TIME, N, ILOG, ISIZE, NOUT, PLB, PUB, TLB, TUB)

WRITE(6 ,140)

140 F0RMAT(1H1 ,*FLOWRATE (LB/MIN) VS. TIME (MINUTES)*)

CALL PPC ( FL0W1 , TIME , N , ILOG , I SIZE , NOUT , FLB , FUB , TLB , TUB

)

WRITE( 6 ,150)

150 FORMAT ( 1H1 ,*POUNDS IN VAPOR PHASE VS. TIME (MINUTES)*)

CALL PPC(MVAP ,TIME ,N , ILOG , ISIZE , NOUT , VLB , VUB , TLB , TUB)

WRITE(6 ,160)

160 FORMAT( 1H1 , *POUNDS IN LIQUID PHASE VS. TIME (MINUTES)*)

CALL PPC(MLIQ, TIME, N, ILOG, ISIZE, NOUT, LLB, LUB, TLB, TUB)

STOP

END

99
PSDATA

4 . 4 . 60 . 1 . OXYGEN

64

0 . 5 . -400 . 100 . 0 . 50 . 0 . 10000 . 0 . 1000

001 48.699 2.75189 3398.11

002 37 .590 4.42648 3398.11

003 26.672 6.02568 3398.11

004 15.938 7.55134 3398.11

005 5.384 9.00520 3398.11

005 -4.998 10.38895 3398.11

006 - 15.211 11.70422 3398.11

007 -25.260 12.95254 3398.11

008 - 35.151 14.13541 3398.11

009 -44.889 15.25425 3398.11

010 - 54.477 16.31042 3398.11

Oil - 63.921 17 .30522 3398.11

012 -73.224 18.23991 3398.11

013 - 82.391 19.11569 3398.11

014 - 91.425 19.93369 3398.11

015 -100.331 20.69502 3398.11

016 - 109.113 21 .40072 3398.11

016 -117.773 22.05177 3398.11

017 - 126.316 22.64913 3398.11

018 -134.745 23.19370 3398.11

019 - 143.064 23.68633 3398.11

020 -151 .276 24.12782 3398.11

021 - 159.383 24.51894 3398.11

022 - 167.390 24.86040 3398.11

023 - 175.299 25.15287 3398.11

024 - 183.114 25.39698 3398.11

025 - 190.836 25.59330 3398.11

026 -198.469 25.74237 3398.11

026 -206.015 25.84467 3398.11

027 -213.476 25.90064 3398.11

028 - 220.856 25.91069 3398.11

029 -228.155 25.87516 3398.11

030 - 235.376 25.79435 3398.11

031 -242.520 25.66852 3398.11

032 -249.589 25.49788 3398.11

033 -256.583 25.28260 3398.11

034 -263.502 25.02281 3398.11

035 -270.347 24.71859 3398.11

036 - 277.115 24.37000 3398.11

037 -283.805 23.97707 3398.11

037 - 290.413 23.53982 3398.11

038 -295.604 23.06581 3398.11

145 - 291.025 21 .25714 2628.10

253 -292.181 19.97737 2628.10

360 - 293.033 19.07144 2628.10

467 -293.684 18.40162 2628.10

575 - 294.195 17.88860 2628.10

. 10000 . 0 . 10000 . 0 . 100 . 0 . 100 . .1 0.0 3.1 0.000 8.601

.2 0.0 6.2 0.000 5.954

.3 0.0 9.3 0.000 4.107

.4 0.0 12.4 0.000 2.671

.5 0.0 15.5 0.000 1.493

.6 0.0 18.6 0.000 .494

.7 0.0 21.7 0.000 0.000

.8 0.0 24.8 0.000 0.000

.9 0.0 27.9 0.000 0.000

.0 0.0 31.0 0.000 0.000

.1 0.0 34.1 0.000 0.000

.2 0.0 37.2 0.000 0.000

.3 0.0 40.3 0.000 0.000

.4 0.0 43.4 0.000 0.000

.5 0.0 46.5 0.000 0.000

.6 0.0 49.6 0.000 0.000

.8 0.0 52.8 0.000 0.000

.9 0.0 55.9 0.000 0.000

.0 0.0 59.0 0.000 0.000

.1 0.0 62.1 0.000 0.000

.2 0.0 65.2 0.000 0.000

.3 0.0 68.3 0.000 0.000

.4 0.0 71.4 0.000 0.000

.5 0.0 74.5 0.000 0.000

.6 0.0 77.6 0.000 0.000

.7 0.0 80.7 0.000 0.000

.8 0.0 83.8 0.000 0.000

.9 0.0 86.9 0.000 0.000

.0 0.0 90.0 0.000 0.000

.1 0.0 93.1 0.000 0.000

.2 0.0 96.2 0.000 0.000

.3 0.0 99.3 0.000 0.000

.4 0.0 102.4 0.000 0.000

.5 0.0 105.5 0.000 0.000

.6 0.0 108.6 0.000 0.000

.7 0.0 111.7 0.000 0.000

.8 0.0 114.8 0.000 0.000

.9 0.0 117.9 0.000 0.000

.0 0.0 121.0 0.000 0.000

.1 0.0 124.1 0.000 0.000

.2 0.0 127.2 0.000 0.000

.3 0.0 130.3 0.000 0.000

.0 293.3 409.3 0.000 0.000

.0 583.2 691.3 0.000 0.000

.1 871.1 973.2 0.000 0.000

.4 1157.8 1255.2 0.000 0.000

.5 1443.6 1537.1 0.000 0.000

'. 0

36

9 12

15

18

21

24

27

31

34

37

40

43

46

49

52

55

59

62

65

68

71

74

77

80

83

86

90

93

96

99

102

105

108

111

114

117

121

124

127

130

116

108

102

97

93

100
.682 - 294.606 17.48423

.789 - 294.942 17.15792

.896 - 295.223 16.88937

1.004 - 295.461 16.66470

1.111 - 295.664 16.47408

1.218 - 295.840 16.31039

1.325 -295.994 16.16835

1.433 - 296.130 16.04397

1.540 - 296.251 15.93416

1.647 - 296.358 15.83652

1.755 -296.455 15.74914

1.862 - 296.543 15.67050

1.969 - 296.622 15.59936

2.076 - 296.694 15.53469

2.184 - 296.761 15.47565

2.291 - 296.822 15.42154

2.355 - 296.867 15.38141

2628.10 90.3 1728.8

2628.10 87.4 2013.5

2628,10 84.9 2298.0

2628,10 82.6 2582.2

2628.10 80.5 2866.3

2628.10 78.5 3150.1

2628.10 76.7 3433.9

2628.10 74.9 3717.6

2628.10 73.3 4001.2

2628.10 71.7 4284.7

2628.10 70.1 4568.2

2628.10 68.6 4851.6

2628.10 67.2 5135.0

2628.10 65.7 5418.4

2628.10 64.3 5701.7

2628.10 63.0 5985.0

2628.10 61.9 6211.6

1819.0 0.000 0.000

2101.0 0.000 0.000

2382.9 0.000 0.000

2664.8 0.000 0.000

2946.8 0.000 0.000

3228.7 0.000 0.000

3510.6 0.000 0.000

3792.5 0.000 0.000

4074.5 0.000 0.000

4356.4 0.000 0.000

4638.3 0.000 0.000

4920.3 0.000 0.000

5202.2 0.000 0.000

5484.1 0.000 0.000

5766.0 0.000 0.000

6048.0 0.000 0.000

6273.5 0.000 0.000

101
NOPLOT

/JOB

/NOSEQ

C0MB0(T500)

/READ, ACCOUNT

HEADING. OLOUIE

GET, COMBO, BOXB ,TAPE5=DATAIN ,TAPE7=FUEL

.

FTN, I=C0MB0,0PT=2,L=TRACE,R=3,PMD.

LDSET ( PRESET =ZERO

)

LOAD, BOXB.

LGO.

SKIP, PASS.

EXIT.

REWIND, TRACE.

COPYEI, TRACE, TAPE6.

ENDIF,PASS.

REWIND, TAPE8.

COPYEI, TAPE8,PSDATA.

REPLACE, PSDATA.

DAYFILE,TAPE6.

REWIND, TAPE6.

COPYEI, TAPE6,PS0UT.

REPLACE, TAPE6,PS0UT.

DAYFILE,DAYF.

REPLACE, DAYF.

/EOI

102
LIBPLOT

/JOB

/NOSEQ

FPL0T(T500)

/READ, ACCOUNT

GET , PSDATA , FPLOT

.

ATTACH

,

STAR4 /UN=CAMLIB , NA

.

LIBRARY, STAR4

.

FTN

,

I=FPLOT , B=B ,L=0 , R=3

.

LOAD

,

B . EXECUTE, , ,

, PSDATA.

/READ, SPY

SUBCOM

/JOB

/NOSEQ

COMBO(T500)

/READ, ACCOUNT

HEADING. OLOUIE

GET , COMBO , BOXB , TAPE5=DATAIN , TAPE7=FUEL

.

FTN , I=COMBO , OPT=2 ,L=TRACE,R=3 ,PMD.

LDSET(PRESET=ZERO)

LOAD, BOXB.

LGO

.

SKIP, PASS.

EXIT.

REWIND, TRACE.

COPYEI, TRACE, TAPE6.

ENDIF ,PASS

.

REWIND, TAPE8

.

COPYEI ,TAPE8 , PSDATA.

REPLACE, PSDATA.

REWIND, TAPE8.

ATTACH , STAR4 /UN=CAMLIB, NA

.

LIBRARY , STAR4

.

GET, FPLOT.

FIN , I=PLOT , B=B ,L=LIST ,R=3

.

LOAD ,B

.

EXECUTE, ,TAPE8.

SKIP, OK.

EXIT.

REWIND, LIST.

COPYEI, LIST, TAPE6

.

ENDIF, OK.

DAYFILE ,TAPE6

.

REWIND, TAPE6

.

COPYEI ,TAPE6 ,PSOUT

.

REPLACE , TAPE6 , P SOUT

.

DAYFILE, DAYF.

REPLACE ,DAYF

.

/EOI

103
DATA IN

$NAME

QPIPE = 1000000.,

$

FUEL

IFUEL

NGAS=2,

$

104
Oxygen Default Parameters

Supply tank initial conditions:

Pressure = 20.000 psia

Temperature = -315.000 F Oxygen Mass = 6270.00 Pounds

Heat Leak = 0.000 Btu/hr

Receiver tank initial conditions:

Pressure = Temperature = Vent Pressure = Tank Volume = Tank Wal 1 Mass = Heat Leak =

Transfer Parameters:

1.000 psia

60.000 F 30.000 psia

300.000 Cubic Feet

350.000 Pounds

0.000 Btu/hr

Pipe Diameter = Length of Straight Pipe =

20 Elbow(s)

0 Gate Valve(s)

2 Globe Valve(s)

1 Angle Valve(s)

0 Butterfly Valve(s)

1 Flow Meter (s)

Heat Leak Into Piping =

Pump Power = Cool-Down Time =

4.000 Inches

100.000 Feet

104400.000 Btu/hr

4.0 HP

1.000 Minutes

Cool-Down Parameters:

Length of Piping = Header Diameter = Nozzle Diameter = Number of Nozzles =20.000 Feet

0.5000 Inches

0.1250 Inches

6

At 1.92 minutes from start of propellant transfer the supply tank is empty.

At this time the, receiver tank is at -310.17 Deg F, 6.65 psia, and contains

6270.00 pounds of oxygen.

During the simulation 0.00 pounds were vented.

105
PRESSURE

(PSIfl)

TEMPERATURE

(DEG

F)

OXYGEN PROPELLENT TRRNSFER

100.0

1

DIAMETER: 4.0 IN.

PUMP: 4.0 HP

TANK TEMP: 60.0 DEG F

TANK PRESS: 1.0 PS I

A

-400.0 H 1—

0.0 0.5

~l

1.0

1—

1.5

“I

2.0

TIME

n 1

2.5 3.0

(MINUTES)

~i

3.5

"i

4.0 4J5 5.0

50.0-!

40.0-

30.0-

20.0

10.0

0.0

0.0 0

T.5

“I T 1 ~1 1 1 1 1

1 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

TIME (MINUTES)

* Computer generated plots.

106
OXYGEN PROPELLANT TRANSFER

(PAGE 21

LJ

CO

cn

JZ

Q_

cno

Q_a=

z:

i—

i

coQ

O

Q_

n

CD

X

LJ

CO

a=

JZ

o_

o

ai—

i

CO

o

2:

ZDOCllO?
FLOWRATE

(POUNDS/MIN)

*10

TOTRL

POUNDS

TRANSFERRED

X

10.0 n

OXYGEN PROPELLENT TRANSFER

(PAGE 3)

8 . 0

-

6 . 0

-

4.0-

2 . 0

-

0.0 ~l

2.5

~T

3.0

TIME (MINUTES)

~i 1—

3.5 4.0

”1

1 4.5 5.0

108
OXYGEN PROPELLRNT TRRNSFER

(PAGE 4)

1007. VflP,

1

LEGEND

- SUPPLY

o - RECEIVER INLET

1007. LIQ, -as

( 1 1 0.0 0.5 1.0 1.5 ”1—

2.0

TIME

2.5 3.0

(MINUTES)

3.5 4.0 -1—4.5 5.0

109
TEMPERATURE

(DEG

F)

HYDROGEN PROPELLRNT TRRNSFER

n

1 r

110
POUNDS

IN

LIQUID

PHRSE

HYDROGEN PROPELLANT TRANSFER

(PRGE 2)

500.0-t

QJ

CO

cn

JZ

Cl. cno

CLcn

coo

CL

3.5 4.0 4.5 5.0

111
FLOWRATE

(POUNDS/MIN)

TOTAL

POUNDS

TRANSFERRED

HYDROGEN PROPELLENT TRRNSPER

(PAGE 3)

112
HYDROGEN PROPELLRNT TRRNSFER

(PRGE 4)

1007. VRP

LEGEND

- SUPPLY

o - RECEIVER INLET

1007. LIQ. -e-s

i

1

0.0 0.5

!

, 2.5 3.0

(MINUTES)

~i—

3.5

i

1.0 1.5 2.0 4.0

TIME

4.5 5.0

113
NOMENCLATURE

The units used in the computer model and derivation of equations are given

first and are followed by SI units, which are enclosed in parentheses.

bp

C

C

C

1

C-,

r ^ii

w

D

dm

f

F(P)

h

L

L

e M

m,

m

N

P

AP

AP

w

Re

cooldown

AP

Q

Q

meter

total

T

brake horsepower for a pump, HP, (W)

conversion factor used in Equations (28) and (29)

constants used in Equation (17)

constant used in Equation (30)

constants used in Equation (39)

constant pressure heat capacity, Btu/(lb*°F), (J/(gmol*K))

constant volume heat capacity, Btu/(lb-°F), (J/(gmol*K))

constant pressure heat capacity of receiver tank wall,

Btu/(lb-°F), (J/ (gmol • K))

pipe diameter, inches, (cm)

differential mass or flowrate of fluid, lb/min, (gmol/s)

Fanning friction function factor, dimensionless

term defined in Equation (lib)

specific enthalpy, Btu/lb, (J/gmol)

pipe length, ft, (m)

equivalent length of a pipefitting, ft, (m)

molecular weight, lb/mol, (g/gmol)

tank wall mass, lb, (g)

propellant quantity, lb, (moles)

Reynolds number, dimensionless

pressure, atm, (MPa)

pressure drop between supply and receiver tanks, atm, (MPa)

pressure drop in the cooldown piping, atm, (MPa)

pressure drop across flowmeter, atm, (MPa)

heat flux in the receiver tank, Btu/hr, (W)

total heat flux in the system, Btu/hr, (W)

temperature, °F, (K)

114
u total internal energy, Btu, (J)

u specific internal energy, Btu/lb, (J/gmol)

u bbulk velocity, ft/s, (m/s)

V tank volume, cu.ft, (£)

V specific volume, cu. ft/lb, (£/gmol)

w work, Btu/hr, (J/s)

X quality of fluid, dimensionless

X dummy variable used in Equation (15)

a bulk thermal expansivity,

-jjj (fyj^ dimensionless

e pipe roughness, ft, (m)

n pump efficiency, dimensionless

e heat of expulsion, -p^ Btu/lb> (J/gmol)

M viscosity, lb/(ft*s), (gmol/(m*s))

P density, lb/ft3

, (gmol/£)

Gruneisen parameter, K

.. . ,

’ p\8u/p T\9p/s , dimensionless

Subscripts

£ 1 iquid

V vapor

1 main fill line into receiver tank

2 receiver tank vent line

cool cool down piping

i either stream 1 or 2

mai n main transfer piping

0 orifice in cooldown piping

RT receiver tank

s supply tank

sat saturated conditions

w tank wal

1

115
REFERENCES

[1] Brux, A.F.; A.J. Stefan, "Suborbital Recovery of External Tank

Propellants", Rockwell International, May, 1982.

[2] McCarty, Robert D. , Interactive Fortran IV Computer Programs for the

Thermodynamic and Transport Properties of Selected Cryogens (Fluids

Pack) , NBS Technical Note 1025, National Bureau of Standards, Boulder,

Colorado, 1980.

[3] McCarty, Robert D. , Hydrogen Technological Survey - Thermophysical

Properties, National Aeronautics and Space Administration, Washington,

D.C. , 1975.

[4] McCarty, Robert D. ; Lloyd A. Weber, "Thermophysical Properties of Oxygen

from the Freezing Liquid Line to 600 R for Pressure to 5000 Psia, NBS

technical Note 384, National Bureau of Standards, Boulder, Colorado,

1971.

[5] Younglove, B. A., "Thermophysical Properties of Fluids. 1. Argon,

Ethylene, Parahydrogen , Nitrogen, Nitrogen Trifluoride, and Oxygen",

Journal of Physical and Chemical Reference Data, 11 (1982) Supp.l.

[6] Bennett, C.O.; J.E. Myers, Momentum, Heat, and Mass Transfer , 2nd

edition, McGraw-Hill, New York, 1974.

[7] Arp, V., J.M. Persichetti and G. Chen, "The Gruneisen Parameter in

Fluids," Journal of Fluids Engineering, 106 (1984) 193.

[8] Olujic, Zarko, "Compute Friction Factors Fast for Flow in Pipes",

Chemical Engineering, December 14 (1981) 91.

[9] Carnahan, Brice; H. A. Luther; J. 0. Wilkes, Applied Numerical Methods , John Wiley & Sons, Inc., New York, 1969.

[10] Sunstrand Aviation Mechanical Brochure No. 9006692, Cyrogenic Pump Model

044018, Sunstrand Corporation, Rockford, Illinois.

[11] Sunstrand Aviation Mechanical Brochure No. 9006592, Cyrogenic Pump Model

044015, Sunstrand Corporation, Rockford, Illinois.

[12] Handbook on Materials for Superconducting Machinery , Metals and Ceramics

Information Center, Battelle, Columbus, Ohio 43201, January 1977.

[13] Mann, D. B. , Ed. , LNG Materials and Fluids , Cryogenics Division, National

Bureau of Standards, Boulder, Colorado, 1977.

[14] Bridgman, P. W. , Condensed Collection of Thermodynamic Formulas , Harvard

University Press, Cambridge, Mass. , 1926.

[15] DISSPLA, Version 9 , Integrated Software Systems Corporation, San Diego,

California, 1981.

116 JJ-U.S. GOVERNMENT PRINTING OFFICE:1985—578-700 / 25188
U.s. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication Date BIBLIOGRAPHIC DATA

SHEET (See instructions)

REPORT NO. NBSIR 85-3023 April 1985

4. TITLE AND SUBTITLE

Cryogenic Propellant Scavenging

Final Report

August 1985 - March 1985

5. AUTHOR(S)

B. Louie, N. J. Kemp, and D. E. Daney

6. PERFORMING ORGANIZATION (If joint or other than NBS. see in struction s) 7. Contract/Grant No.

national bureau of standards

DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered 1 WASHINGTON, D.C. 20234

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City, State, ZIP)

National Aeronautics and Space Administration

Lyndon B. Johnson Space Center

Houston, Texas 77058

10. SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information,

bi bl iography or literature survey, mention it here)

If document includes a significant

This report is a detailed description of a computer model that has been

developed for assessing the feasibility of low g cryogen propellant scavenging

from the Space Shuttle External Tank (ET). Either pump-assisted or pressureinduced propellant transfer may be selected. The receiver tank is chilled by

emitting a low flowrate of single-phase cryogen through small nozzles. When

two phases are present the flowrate is increased to represent transfer through

the main piping. The program will accept a wide range of input variables,

including the fuel to be transferred (LOX or LH 2 ), heat leaks, tank temperatures

,

and piping and equipment specifications.

The model has been parametrically analyzed to determine initial design

specification for the system. Pressure-induced transfer of tH 2 can be

accomplished in approximately 7 minutes with a 3-inch (0.076 m) line size.

Pump-assisted scavenging of LOX can be completed in less than 4 minutes by

using a 2 HP (1491.4 W) pump and a 3-inch (0.076 m) line. To maximize the

quantity of LH2 recovered, the receiver tank should be prechi lied to -290 °F

(94.1 K). It was determined that the LOX receiver tank does not require

prechilling and can have a temperature as warm as 300 °F (421.9 K) without

significant venting of fluid.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate ke

y

c rd computer model ; cryogenic; fluid transfer; low-g; scavenging; thermodynamics

13. AVAILABILITY

| X I Unlimited

| 1 For Official Distribution. Do Not Release to NTIS

| | Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

[Xj Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED Pt

124

GES

15. Price