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I
NBSIR 75-820

STUDY OF CRYOGENIC PROPELLANT SYSTEMS

FOR LOADING THE SPACE SHUTTLEPART II, HYDROGEN SYSTEMS

W.G. Steward

Cryogenics Division

Institute for Basic Standards

National Bureau of Standards

Boulder, Colorado 80302

October 1975

Prepared for : National Aeronautics and Space Administration

John F. Kennedy Space Center, Florida 32899

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NBSIR 75-820

STUDY OF CRYOGENIC PROPELLANT SYSTEMS

FOR LOADING THE SPACE SHUTTLEPART II, HYDROGEN SYSTEMS

W.G. Steward

Cryogenics Division

Institute for Basic Standards

National Bureau of Standards

Boulder, Colorado 80302

October 1975

Prepared for : National Aeronautics and Space Administration

John F. Kennedy Space Center, Florida 32899

U.S. DEPARTMENT OF COMMERCE, Rogers C. B. Morton, Secretary

John K. Tabor, Under Secretary

Dr. Betsy Ancke r-Johnson , Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director

CONTENTS

Page

PREFACE 1

1. Introduction 1 1.1 Objective 1

2. Graphic Display Computer Teminal 1 2.1 Description of Equipnent 1 2.2 Description of the >tLniconputer Software 3 2.3 Instructions for Log- In 4 2.4 Instructions for Initiation of Computation in the Automatic Mode ... 5 2.4.1 Required Improvisations for the Hydrogen Input Displays .... 5 2.5 Data Input 6 2.6 Selection of Computation Option 8 2.7 Reloading the Minicomputer Programs 9

3. Computation Options 9 3.1 Option 1 - Thermal Stresses 9 3.1.1 Application 9 3.1.2 Input Data Entries 9 3.1.3 Output 10

3.2 Option 3 - Cooldown Time - length cooled down and flow rate versus time 10

3.2.1 Application 10

3.2.2 Input Data Entries 10

3.2.3 Output 10

3.3 Option 6 - Cold Elow - steady flow operation and transient response

to changes in operating conditions 10

3.3.1 Application 10

3.3.2 Input Data Entries 13

3.3.3 Output 13

4. Nomenclature 19

5. References 20

APPENDIX A - Vent Gas Temperature 21

APPENDIX B - Two Phase Flow 23

APPENDIX C - Loading of the Jlinicomputer 26

The Binary Loader 26

1. Preparing the Teletj^se 26

2. Loading the Program 26 Bootstrapping 26

APPENDIX D - Hydrogen Computer Programs 28

Program CDT - Option 3, Cooldown Time (Flow Diagram) 28

Program CDT - Computer Listing S>Tnbols 32

Program TS - Option 1, Thermal Stresses 36

Program CDT - Option 3, Cooldo^^m Time 36

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Subroutine CDT2FILE - Graph Headings and Labels for CDT 40

Subroutine CDTSUB - Heat Transfer and Pressure Drop Subroutines for CDT . . 41

Program CF - Option 6, Cold Flow (Flow Diagram) 43

Program CF - Computer Listing Symbols . 47

Program CF - Option 6, Cold Flow 50

Subroutine CF2FILE - Graph Headings and Labels for CF 53

Program CFSUB - Pressure Drop Functions for CF 54

Function HPROP - Hydrogen Properties, Vent and Two Phase Flow Functions for CF 55

Subroutine PLOT - Plotting Subroutine for all Programs 57 Program DATFILE - Prints Date and Time on Input and Output Figures 59

LIST OF FIGURES

Figure Page

1. Graphic display terminal and minicomputer 2

2. Log-in sequence 5

3. General input data 6

3A. Hydrogen general input data 7

4. Selection of computation options

.

8

5. Option 1 - thermal stresses input display , 9

6. Option 3 - cooldown time input display 11

6A, Option 3 - cooldown time hydrogen input display 11

7. Option 3 - output 12

8. Option 3 - output (continued) 12

9. Option 6 - cold flow input display 14

9A. Option 6 - cold flow hydrogen input display 14

10. Option 6 - cold flow input display (continued) 15

11. Option 6 - output 15

12. Option 6 - output (continued) 16

13. Option 6 - output (continued) 16

14. Option 6 - output (continued) 17

15. Option 6 - output (continued) 17

16. Option 6 ~ output (continued) 18

Bl. Modified Mar tinelli-Nelson two phase flow factor 24

' ' LIST OF TABLES

Table Page

C-1. Set Switch Register Switch Position 27

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STUDY OF CRYOGENIC PROPELLANT SYSTEMS FOR LOADING THE SPACE SHUTTLE - PART II, HYDROGEN SYSTEMS*

W. G. Steward

ABSTRACT

This report covers computer simulation studies of liquid hydrogen

fill and vent systems for the space shuttle. The computer programs

calculate maximum and minimum permissible flow rates during cooldown

as limited by thermal stress considerations, fill line cooldown time,

pressure drop, flow rates, vapor content, vent line pressure drop and

vent line discharge temperature. The input data for these programs

are selected through graphic displays which schematically depict the

part of the system being analyzed. The computed output is also displayed in the form of printed messages and graphs. Digital readouts

of graph coordinates may also be obtained.

Procedures are given for operation of the graphic display unit

and the associated minicomputer and timesharing computer.

Key words: Computer modeling; cooldown; cryogenic flow; stresses;

two phase flow.

PREFACE

It will be noted that non-SI units appear in many of the figures of this report. The

purpose of these figures is to illustrate typical displays as they appear on the screen

of the graphical display terminal. These units are consistent with the current practice

of KSC and are as desired by the KSC sponsor. l«/here dimensioned variables are mentioned

in the text, dual units are given.

1. Introduction

This is a final report under NASA Contract No. CC-37171A.

This report covers a continuation of computer simulation studies of cryogenic propellant

loading systems for the space shuttle. The preceding report, NBSIR 74-366, covered oxygen

loading systems and the present report extends this work to the hydrogen loading and vent

systems

.

1.1 Objective

The objective of this study is to develop computer programs to determine thermal stress,

cooldown times, and liquid hydrogen loading rates whereby loading procedures can be checked

before a wet test of the actual system is conducted.

The programs of the oxygen studies which compute pressure spikes caused by water hammer

or rapid vaporization during cooldown have been deleted from the hydrogen studies in favor

of a more detailed analysis of the liquid loading rates and vent system. Since the pressure

spikes have amplitudes which are approximately proportional to the density of the liquid,

these spikes would be at least an order of magnitude smaller in hydrogen than in oxygen;

therefore, they would be negligible; therefore, computation options 2, 4 and 5 were deleted

from the hydrogen program. Contrarily, the effects of two phase flow during loading, vent

line temperatures, and vent line pressure drop are factors of concern in the hydrogen

system and were added to the present studies.

2. Graphic Display Computer Terminal

2.1 Description of Equipment

The system consists of a graphical display terminal interfaced with the KSC timeshare

computer through a 8000 word storage minicomputer and MODEM. Figure 1 shows the graphical

display unit and minicomputer.

Software for communication between the display unit and the KSC computer, routines for

schematic displays, input-output, and graphing are programmed into the minicomputer. These

routines are also stored on punched paper tape from which they may be reloaded if necessary.

The programs and subroutines used in the calculations are catalogued in the KSC computer

and are called as needed through the minicomputer software routines.

*This work was conducted at the National Bureau of Standards under the sponsorship of the

Kennedy Space Center - National Aeronautics and Space Administration.

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2.2 Description of the Minicomputer Software

The programs contained in the minicomputer control the information flow between the

graphical display unit and the KSC timesharing computer. Besides the control function, the

minicomputer has the input schematics with the associated input data and programs to interpret the responses received from the KSC timesharing computer (during execution of the

hydrogen ground support computer program) in its memory.

The communication between the minicomputer system and the KSC computer is carried over

a high speed telephone data line. The MODEM properly conditions the signals for the high

speed data transmission.

Data is transmitted in various sized blocks with both horizontal and longitudinal

parity. The receiving station checks for the parity errors in the incoming block of data

and if the parity is correct, the transmission is accepted and an acknowledgment is re- turned to the sending station. If the parity of the received information is not correct,

due to noise or other problems with the telephone line, the receiving station requests a retransmission. The sending station will then automatically retransmit the data. In some rare instances, the retransmission request is lost and the data must be manually retransmitted.

The minicomputer software has two basic modes of operation using the graphical display

keyboard. The first mode, termed the manual mode, allows conversation with the KSC computer

in a manner similar to a normal teletype except that the communication is at a high speed.

The second mode of operation, termed the automatic mode, is used to run the computer programs simulating the hydrogen ground support equipment. Much of the communication between

the minicomputer and the timesharing computer in the second mode is automatic, with no operator input required.

During operation in either mode, the graphical display terminal will emit an audible

"beep" whenever an acknowledgment is received from the timesharing computer. This "beep"

will inform the operator that a data block has been successfully sent and new information can be entered or a return can be expected from the timesharing computer. Until a successful

transmission is affected, the keyboard of the graphical display unit is locked except to a control B, as explained in a later paragraph.

Operation in the manual mode allows for normal log-in procedures and the use of any

subsystems on the KSC computer. Fortran, basic or the editing subsystem, may be employed in

the manual mode.

Since the graphical display-minicomputer combination is connected to a terminal of

the KSC timesharing system, operation in the manual mode is very similar to the general

operation of the system as described in the manufacturer's manual. Log-on procedures as described in the manual are also valid for the graphic display unit.

During operation of the graphic unit, data entered on the screen of the graphics display

are also entered into the memory of the minicomputer and when a carriage return is depressed, the data from the computer memory is transmitted to the timesharing computer. More

than one line of data may be transmitted in a block if each line entered on the screen is

terminated by a line feed and the entire block is terminated by a carriage return for

transmission.

Typing errors can be corrected by using a control A which causes the cursor to be backspaced once and lowered one line. The character typed in the lower position replaces the

original character in the minicomputer memory and will be transmitted when the carriage

return is depressed. Since the graphics display unit is connected to a KSC timesharing

terminal, other characteristics unique to that system affect the operation of the display

unit. As an example, the timesharing computer counts the lines of output during its data

transmission and after sufficient lines have been sent to fill the screen of the display

unit, data transmission is terminated. The stop in data transmission Is Indicated by the

ASCII code characters A * on the screen of the graphics unit. To receive additional data,

the operator must transmit a blank line by depressing the carriage return on the keyboard.

The automatic mode of operation interacts with the specific hydrogen system simulation

programs available in the Fortran subsystem of the timesharing computer. During automatic

operation, the minicomputer will request a run of a specified program; send the required

data when an equal sign is received; and interpret and display returning data from the timesharing computer on the graphical display unit. Usually, the returning data will be displayed

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in graphical form. Since the hydrogen simulation programs are in the Fortran subsystem, the

KSC computer must be in the Fortran subsystem before the automatic mode of operation is

entered with the graphical display unit. The Fortran subsystem of the timesharing computer

is indicated by an asterisk displayed on the screen. Several control characters are used during normal operation of the graphic display unit

to help the operator during the execution of the various programs. A control character is

used during communication between the graphic display unit and the minicomputer and need

not be followed by a carriage return to effect a transmission. A control character is exe- cuted by depressing and holding down the control key on the keyboard and then depressing the

desired alpha-numeric key. Thus, a control D means that the control key was depressed and

held, and then the letter D was depressed. The following is a description of the control

characters available for use on the graphic display unit.

Control A : Control A allows the operator to correct a typing error before a block of

data is sent to the timesharing computer. Any time before the carriage return is depressed,

a change can be made to previously typed material. This change is made by depressing the

control A an appropriate number of times until the cursor is located below the character to be changed, entering the new character and then proceding to enter subsequent characters in

the line. One character is deleted each time control A is depressed.

Control B : Depressing control B will cause the minicomputer to issue a $*$ BRK command

to the timeshare computer and return the minicomputer to the manual mode of operation. The

function of the $*$ BRK command is described in the manufacturer's information manual.

Control B can be used any time even during a transmission when the keyboard is locked to other input.

Control G : Control G causes the minicomputer to enter the automatic mode of operation.

Entering the automatic mode of operation should not be attempted unless the KSC timeshare

computer is operating in the Fortran subsystem and an asterisk (*) is displayed as the last

received character on the graphic display unit.

Control P : Depressing the control P causes the minicomputer software to interpret

data returning from the timesharing computer into graphical output. This option was supplied

with the minicomputer to allow graphical output from any Fortran programs written in the

manual mode. In order to graph the results of any program written in the manual mode, the

output from the program must be supplied to the ASCII coded Fortran subroutine called PLOT

currently available on the timesharing computer. Along with the data, labeling information

can also be supplied to PLOT. The program DEMO currently loaded in the timesharing computer

can be listed to obtain instructions on how to use subroutine PLOT. After writing a program

for which a graphical output is expected the program is run in the manual mode, except that

after all input data has been supplied and acknowledge received as indicated by a "beep";

control P should be depressed. A graph of the returning data will then appear on the graphical display unit

.

2.3 Instructions for Log- In The log- in routine for the minicomputer is accomplished in the manual mode. The procedure is to turn on the Modem (switch located inside the front cover) , the minicomputer

(key switch on front panel) , and the graphics display unit (switch located on the front of

the pedestal below the keyboard) . The line-local switch on the graphics display keyboard

should be set to line. After a short warm-up period, the screen on the graphics display

unit will light up. The page key on the display unit should be depressed to prepare the screen for reception of messages. The starting address of the software program in the minicomputer is 00002 in octal (switch 14 on the top row of toggle switches up, all others down).

After setting the top switches to the starting address, depress RESET and then START on the

momentary contact control switches from the lower row of switches of the minicomputer. The

timesharing computer can now be dialed on the telephone. After the computer carrier signal

(a continuous tone) is confirmed, the telephone data switch can be actuated. As soon as the

minicomputer software confirms the computer interconnections, the words PLEASE LOG IN will

appear on the graphics display screen. If these words do not appear, a fault has developed

in the minicomputer software, or the telephone interconnection was not achieved. The

program should be reloaded as described in appendix C. The normal log- in procedure for

the KSC timesharing system as described in the manufacturer's manual can now proceed. A

carriage return should be supplied after each input to transmit the information to the

timesharing computer. Figure 2 shows the appropriate log- in sequence as it would appear

on the screen of the graphics display unit. Computer supplied messages are underlined.

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2.4 Instructions for Initiation of Computation in the Automatic Mode

In order to perform calculations in the automatic mode using the hydrogen simulations

programs, the Fortran subsystem of the timesharing computer must be available. On figure

2, the Fortran subsystem was entered by entering Fortran for the required system and new

for the type of program. After an asterisk (*) appears on the screen as the last reception,

control G can be depressed to enter the automatic mode of calculation. After initiation of

the automatic mode, the universal figure (fig. 3) will appear on the screen of the graphics

terminal. This figure is used to define the general characteristics of the piping system.

Special procedures are required, however, for the use of the input display for the hydrogen

programs. The necessity for, and the use of these special procedures are explained in

Section 2.4.1.

2.4.1. Required Improvisations for the Hydrogen Input Displays

The data input displays are generated from programs loaded into the minicomputer from

punched paper tape. Since the hydrogen programs require different input variables than the

oxygen programs alternate input displays would be desirable; however, re-loading programs

from paper tape each time the fluid is changed would be highly impractical. Equipment

exists which could load the programs rapidly; however, purchase of additional equipment

was not justifiable for this study. Therefore, it was necessary to improvise a method by

which the required variables could be inserted into the hydrogen programs from the original

oxygen displays. This improvisation was necessary for the "GENERAL INPUT DATA" option 3,

and option 6, "COLD FLOW." The display which appears for option 1, "THERMAL STRESS" is

unaltered and requires no unusual interpretation.

PLEASE LOG IN $*$MD PASSWD, 26, DAC, TSS ****** CONNECT REQUEST SENT TO CP ******

KSC 635 AT GIF ON 02/06/75 AT 10.281 CHANNEL 4424

USER ID - 5ME013

PASSWORD^

ESXHKXHXXZMKMKE

NBSH

9 BLOCKS FILE SPACE AVAILABLE

**TSS SIZE 54K CARDIN 25K

SYSTEM ? TFOR

OLD OR NEW - NEW

READY

Figure 2. Log- in sequence.

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Figure 3 shows the "GENERAL INPUT DATA" as it will appear on the screen of the

graphic display unit. Figure 3A shows the new interpretation of the numbers entered.

For example, item 8 on figure 3 appears as "SUPPLY LIQUID LEVEL = 850,000 FT"; however,

the hydrogen programs interpret this entry as "SUPPLY LIQUID VOLUME = 850,000 GAL". By

comparison of the flow diagrams shown in figures 3 and 3A it may be seen that the pipe

lengths are distributed differently in the hydrogen programs. Lengths L4 through L7 are used to represent parts of the vent line in figure 3A, whereas no vent line lengths are shown in figure 3. In order to avoid confusion a template has been prepared which fits over the screen

of the graphic display unit. The template masks the flow diagram and the wording of the

oxygen display but has windows in which the entered numbers appear. The opaque portion

of the template shows the new flow diagram and the appropriate wording to correspond with

the hydrogen program interpretation of the entered numbers. The graphic display screen with the template in place will then appear the same as figure 3A. A similar template

has been prepared for option 3 "COOLDOWN TIME", and option 6 "COLD FLOW."

2.5 Data Input

In the general input data entry 7, "SUPPLY ULLAGE PRESSURE" requires some clarification

For computation options, except option 6, there is no difference between the ullage pressure

during storage and during the transfer process. For option 6, the pressure specified in

the general input data is taken to be the ullage pressure during storage and it is assumed

that the supply liquid becomes saturated at that pressure. The specific input data for

option 6 allows a "SUPPLY ULLAGE PRESSURE DURING TRANSFER" to be selected which may be

different from the supply ullage pressure during storage.

GENERAL INPUT DATA 03/14/75 8.333

1. LENGTHS:

LI

L2

LI 1606 FT

L2 37 FT

L3 98 FT

L4 24 FT

L5 22 FT

L6 825 FT

L7 1430 FT L8 2350 FT L9 10258 FT LENGTHS L3, L4 =

01 8.33 IN 02 10.482 IN 05 8.33 IN 05 17.50 IN 07 17.50 IN 08 17.50 IN 09 393,400 IN NS:H8 2.9 FT H9 109 FT

10.482 IN

L6

4. AMBIENT TEMPERATURE = 0 DEG F

5. WIND VELOCITY = 0 KNOTS

6. RELATIVE HUMIDITY = 0%

7. SUPPLY ULLAGE PRESSURE = 1.5 PSIG

8. Supply LIQUID LEVEL = 850,000 FT

9. IS THE PIPE VACUUM INSULATED

(0 - YES, 1 - NO) ? 1 10. DOES THE LINE VENT INTO THE TANK (1 OR THE CATCH BASIN (2) ? 1000

L3

L5

L4

Figure 3. General input data.

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GENERAL INPUT DATA

LI

1. LENGTHS: LIL2

L3

L4

L5

L6

L7

L8

L9

2. DIA FOR LENGTHS

D2

D3

D4

D5

D6

D7

LI

1606 FT

37 FT

98 FT

24 FT

22 FT 826 FT 1430 FT 2350 FT 10258 FT

8.33 IN 10.482 IN 8.33 IN 17.50 IN 17.50 IN 10258 IN

(EQUIV. LENGTH AT DIA. (EQUIV. LENGTH AT DIA.

= 10.482 IN

3. CAP. RECVR. TNK = 393,400 GALLONS

4. VENT RATE =2.9 LBM/SEC

5. ELEV. HI = 109 FT

6. PUMP RATED FLOWRATE = 0 GPM

PUMP RATED P. = 0 PSI PUMP RATED SPEED = 0 RPM

7. SUPPLY ULLAGE PRESSURE = 1.5 PSIG

8. SUPPLY LIQUID VOLUME 1 850,000 GAL.

9. INSULATION ON L1-L3 (0-VACUUM, 1-FOAM,

2-BARE) 1 10. ESTIMATED HEAT LEAK DUE TO COUPLINGS 1000 BTU/HR

L2

L3

Figure 3A. Hydrogen general input data.

It will be noted that in figure 3A there are two lengths, L8 and L9, which are listed

but which are not shown in the schematic flow diagram. L8 is an equivalent length of pipe

of diameter D3 to represent pressure losses due to valves, fittings, flex hose, filters,

etc. in addition to the actual lengths LI through L3 in the fill line. L9 is a similar

equivalent length of pipe of diameter D6 to represent additional pressure losses in the vent line.

Since the flow in the fill line is considered incompressible a standard method of

determining the equivalent length as given by most manufacturers of valves and fittings may

be used. When the pressure drop element is located in a pipe having a diameter other than

D3 the following equation may be used:

L8 = L (D3/D

P P where is the equivalent length as given by the manufacturer and is the diameter of

the pipe in which the valve or fitting is installed.

In the vent line variations in gas density must be considered as well as changes in

diameter when assigning a value to equivalent length L9. This density change is due to changes in absolute temperature to a much greater extent than to changes in absolute pressure. Since the pressure drop for a given mass flow rate is inversely proportional to

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density and density is approximately inversely proportional to the absolute temperature:

L9 = L (T /T,)(D6/D

p p 6 p where T is the temperature at the location of the pressure drop element and T, is the

P o temperature at the discharge end of length L6. These temperatures may be estimated by

assuming a linear variation of temperature along the vent line, a vent inlet temperature

of approximately 20 K (36°R) and a vent discharge (bubble cap) temperature obtained from

a preliminary run of computer option 6. When the input figures appear, the input variables will contain the numbers used in

the previous run of the program. The first time the hydrogen programs are used following

operation of the oxygen programs most of the hydrogen data will have to be re-entered

since the data in the minicomputer memory will be oxygen rather than hydrogen data. The

reverse situation will exist when oxygen programs are first used following operation of

the hydrogen programs; i.e., most of the oxygen data will have to be re-entered.

On succeeding runs with the same fluid any or all input numbers may be changed. A

change is accomplished by moving the horizontal cursor to the line containing the number

to be changed, pressing the "RUB OUT" key, then typing the new number in the blank space

which will appear. After pressing "RETURN" the operator may move the cursor and make further

changes. Even though the schematic will not change, the computer programs will accept zero

for lengths 2 and 3 (L2, L3) to eliminate the vertical rise if desired and will accept a single pipe length equal to the total pipe length and a single diameter. At the upper right

on the figure, the current date and time will appear. This date and time will remain the same and will appear on all subsequent figures to be used as an identification number to correlate hardcopy output. After all input parameters have been adjusted to acceptable

values, and the ALT MODE key is depressed, the system will proceed to the next page.

2.6 Selection of Computation Option

This page (fig. 4) allows a choice of the computer program to be run with the previous

input data. (As was noted earlier, options 2, 4, and 5 are not available for the hydrogen

system). After this choice is made by placing the option number in the appropriate blank

SELECTION OF COMPUTATION OPTIONS 03/07/75 9.618

SELECT ONE OF THE FOLLOWING COMPUTATION OPTIONS:

1. OPTION 1 - THERMAL STRESSES. STRESSES DUE TO RAPID COOLDOWN OF FLANGES,

OR BOWING OF PIPELINE DUE TO STRATIFICATION IN THE CASE OF LOW FLOW RATES.

2. OPTION 2 - VALVE OPENING SURGES. SURGES DUE TO RAPID VAPORIZATION WHEN

A VALVE IS OPENED PRECEDING A FREE WHEELING PUMP. ALSO CALCULATED IS THE PRESSURE PEAK DUE TO WATER HAMMER AS THE LIQUID IMPINGES ON A FREE WHEELING

PUMP.

3. OPTION 3 - COOLDOWN TIME. CALCULATES LENGTH COOLED DOWN, FLOW RATE, AND

PRESSURE DROP ACROSS THE PUMP VERSUS TIME.

4. OPTION 4 - PUMP START UP COOLDOWN SURGES. CALCULATES SURGES DUE TO RAPID

VAPORIZATION WHEN A PUMP IS STARTED UPSTREAM FROM A WARM LINE.

5. OPTION 5 - WATER HAMMER. PRESSURE SPIKES DUE TO WATER HAMMER WHEN VALVES

ARE CLOSED IN A FLOWING LIQUID STREAM.

6. OPTION 6 - COLD FLOW. STEADY FLOW OPERATION AND TRANSIENT RESPONSE TO

CHANGES IN OPERATING CONDITIONS.

7. OPTION 7 - RETURN TO MONITOR.

OPTION SELECTED IS 1

Figure 4. Selection of computation options.
and depressing ALT MODE, the terminal will display the first page of that option. The

first page of each option, plus as many as two more pages will appear, allowing for more specialized input data. Typical display figures are shown in the following sections.

After the input data has been adjusted as previously described and ALT MODE depressed for

each input figure, the output of each option will appear after a short period of time.

During this time interval, several "beeps" will be heard as input data is supplied to the

timesharing computer. In some instances, when multiple output is expected, a choice of

output curves will be made available. Each output curve will fill the entire screen. When the output curve appears, it will be possible to digitize any point on the curve by

placing the vertical cursor on the desired point and depressing the space bar, and a hard

copy may be obtained by depressing control D. Restarting with the input display is accomplished by depressing ALT MODE. At this

time the operator may choose another computation option with the previous input values, he

may change the input, or he may terminate computation by selecting option 7 from the

second page (RETURN TO MONITOR). Of course, if the operator chooses to start calculations

on a new system, a new date and time will appear on all figures, allowing him to maintain

correlation between the input and the output figures.

2.7 Reloading the Minicomputer Programs

Several paper tapes have been supplied with the system. Some of the tapes were

supplied by the manufacturer of the minicomputer and can be used to debug the hardwired

functions of the minicomputer. The function of the manufacturer's supplied tapes are described in accompanying literature. Other paper tapes can be used to reload the existing

minicomputer program. The paper tape loading procedure using an appropriate teletype unit,

is described in Appendix C.

3.1 Option 1 - Thermal Stresses

Calculates stresses due to rapid cooldown of flanges, or bowing of pipeline due to stratification in the case of low flow rates. 3.1.1 Application

This computation determines low and high limits of flow rates during cooldown from

the standpoint of the resulting stresses in the piping system and flanged joints. For very high flow rates and rapid cooling excessive thermal stresses may be created in

flanges due to the large radial temperature gradients. On the other hand very low flow

rates might result in stratified flow with liquid lying along the bottom of the pipe.

The resulting circumferential temperature gradients could cause a pipeline to bow significantly. These stress-limited cooldown flow rates are calculated according to the method

of Novak [1970].

3.1.2 Input Data Entries

Section 2.3 describes the general log- in procedure for the graphic display system.

After the initial log- in has been accomplished, and option 1 has been selected, a display

similar to figure 5 appears. The input required for this option in addition to the general

3. Computation Options

03/07/75 9.618

OPTION 1 - THERMAL STRESSES

1. OUTSIDE DIAMETER OF PIPE FLANGE IS 18 IN

2. OUTSIDE DIAMETER OF PIPELINE IS 14 IN

3. INSIDE DIAMETER OF PIPELINE, IS 10.482 IN

4. PIPELINE MATERIAL IS NUMBER 2 CHOICE OF PIPELINE MATERIAL:

1 ALUMINUM

2 304 STAINLESS STEEL

Figure 5. Option 1 - thermal stresses input display.
input data of figure 3 is shown in figure 5. These are the outside diameter of the pipe

flange, the outside and inside diameters of the pipeline and the material of the pipeline.

3.1.3 Output

The output for this calculation is alpha numeric only but will be displayed on the screen just as other output data. The values given will be the maximum cooldown flow rate

which will allow the stress in the flanges to remain below the yield point, and the minimum

flow rate which will prevent stratified flow from occurring with the given input conditions.

3.2 Option 3 - Cooldown Time - length cooled down and flow rate versus time.

3.2.1 Application

As a cryogenic liquid flows or is pumped from a reservoir into a warm pipeline, vapor

forms at the leading end of the liquid stream. Frictional resistance to the flow of this

vapor is the principle limiting factor in the rate of cooling pipelines of large lengthto-diameter ratios. The slow moving liquid is evaporated and vapor is warmed to near the

initial temperature of the pipe in a short distance relative to the length of pipe. When

the pipeline is uninsulated, the heat transfer to the cold part of the pipe adds to the

vaporization rate and thus further retards the progress of the liquid. The cooldown model

based on this cold front concept and listing of the computer subroutine (CDT) are discussed

in Supplement A (1974) . The heat-mass transfer correlations are discussed in Appendix A

of NBSIR 74-366 (Voth, et al, 1974).

3.2.2 Input Data Entries

Section 2.3 describes the log- in procedure for the graphic display system. After the

initial log- in has been accomplished and option 3 "Cooldown Time" has been selected, a display similar to Figure 6 appears. As discussed in section 2.4 this display is a part of

' the minicomputer program designed for the oxygen system. It is apparent from Figure 6 that

the input display accommodates six different pipe sections, three wall materials and three

thicknesses. Since it was necessary to limit the number of hydrogen fill line sizes to three

(LI, L2, and L3) , the three extra material and thickness variables had to be eliminated.

Figure 6A shows the resulting interpretation of the hydrogen input data for the cooldown time

program. It can be seen that entries 3 through 8 remain unchanged.

If desired, input variables pertinent to the cooldown time computation may be viewed

and changed on this display as explained in Section 2.4. The variables in figure 6A apply

only to option 3 and are in addition to those of the general input data of figure 3. Concentrated masses such as valves, pumps, and fittings should be compensated for by specifying

additional pipe wall thickness provided the calculated cooldown time desired is to include

the time needed to completely cool these concentrated masses.

3.2.3 Output

The outputs of the computation are: (1) length cooled down versus time, (2) flow

rate of liquid hydrogen versus time, and (3) pressure drop across the pump (if a pump

exists) versus time. Typical examples are shown in figures 7 and 8. The x and y values

shown in figure 7 and subsequent output graphs are the result of digitizing. In figure 7 x corresponds to time and y corresponds to length cooled.

3.3 Option 6 - Cold Flow - steady flow operation and transient response to changes in operating conditions.

3.3.1 Application

This computation applies after the transfer line has reached operating temperature.

It deals with response to changes in operating conditions but does not deal with cooldown

transients. The latter are treated separately in option 3. The flow rate and receiver

tank liquid temperature (or two phase quality) are calculated as functions of the supply

ullage pressure and pipe geometry. The accumulated liquid, change in supply liquid level,

and vent bubble cap temperature are also computed. Supply ullage pressure and valve

settings are allowed to vary with time. Details of the computation and computer program

listing are given in Supplement A (1974), and Appendix D of this report.

10
OPTION 3 - COOLDOWN TIME 03/10/75 15.066

PIPE WALL DATA: MATERIALS - ENTER

1

2

3

FOR

STAINLESS STEEL

ALUMINUM

INVAR

1. MATERIAL OF PIPE FOR LENGTHS

LI, L2, L3, L4 IS 3 FOR L5 IS 3 FOR L6 IS 3 FOR L7 IS 0 FOR L8 IS 0 FOR L9 IS 0

2. WALL THICKNESS FOR LENGTHS

LI, L2, L3, L4 IS .134 IN FOR L5 IS .134 IN FOR L6 IS .134 IN FOR L7 IS 0 IN FOR L8 IS 0 IN FOR L9 IS 0 IN

3. LENGTH OF LINE TO BE COOLED IS 4090 FT

4. IS A PUMP PRESENT IN THE SYSTEM

(0 - NO, 1 - YES)? 0

5. IF THERE IS A PUMP, DOES IT FREEWHEEL

DURING COOLDOWN (0) OR IS IT STARTED

AFTER A SPECIFIED TIME (1)? 1

6. IF THE PUMP IS STARTED, HOW LONG AFTER

COOLDOWN IS IT STARTED? 35 MIN

7. IF THE PUMP IS STARTED, AT WHAT SPEED

DOES IT RUN? 1000 RPM

8. OUTPUT DESIRED IS 1

(1) LENGTH COOLED DOWN VS. TIME

(2) FLOW RATE OF LOX VS. TIME

(3) PRESSURE DROP ACROSS PUMP VS. TIME

ZiSyi!S_6i QE£i2B_3_z_cooldown_time_in£ut_dis£la^^

OPTION 3 - COOLDOWN TIME

PIPE WALL DATA: MATERIALS - ENTER

1

2

3

FOR

STAINLESS STEEL

ALUMINUM

INVAR

1. MATERIAL OF PIPE FOR LENGTHS

LI IS 3 L2 IS 3 L3 IS 3

2. WALL THICKNESS FOR LENGTHS

LI IS .134 IN L2 IS .134 IN L3 IS .134 IN

3. LENGTH OF LINE TO BE COOLED IS 4090 FT

4. IS A PUMP PRESENT IN THE SYSTEM

(0 - NO, 1 - YES)? 0

5. IF THERE IS A PUMP, DOES IT FREEWHEEL

DURING COOLDOWN (0) OR IS IT STARTED

AFTER A SPECIFIED TIME (1)? 1

6. IF THE PUMP IS STARTED, HOW LONG AFTER

COOLDOWN IS IT STARTED? 35 MIN '

7. IF THE PUMP IS STARTED, AT WHAT SPEED

DOES IT RUN? 1000 RPM

8. OUTPUT DESIRED IS 1

(1) LENGTH COOLED DOWN VS. TIME

(2) FLOW RATE OF LOX VS. TIME

(3) PRESSURE DROP ACROSS PUMP VS. TIME Figure 6A. Option 3 - cooldown time hydrogen input display.

11
03/18/75 10.460

LIQUID IS DRIVEN BY ULLAGE PRESSURE AND STATIC HEAD

THERE IS NO PUMP IN THE SYSTEM

2000,— 3.32E+00 1 .76E+03

oa

UJ

1600

1200

800

400

6000

1

0.70 1.40 2.10 2.80 3.50

TIME IN MINUTES

Figure 7. Option 3 - output.

03/18/75 10.598

LIQUID IS DRIVEN BY ULLAGE PRESSURE AND STATIC HEAD

THERE IS NO PUMP IN THE SYSTEM

TOTAL LIQUID INFLOW 4695 LBS, TOTAL VENT 521 LBS

X = 3.32E+00,

X = 3.51E+00,

7.43E+03

1 .66E+04

4800

3600

2400

1200

0.70 1.40 2.10

TIME IN f II NOTES

2.80 3.50

Figure 8. Option 3 - output (continued).

12
3.3.2 Input Data Entries

Section 2.3 describes the general log-in procedure for the graphic display system.

After the option 6 is selected, a display similar to figure 9 and 10 will appear. Figure

9, as with all the input data displays, is contained in the minicomputer memory and was designed for the oxygen system. Several changes were desired for the hydrogen programs:

1. Under item 3, the output options "RECEIVER LIQUID TDIPERATORE" to replace "Pr.-IP DISCHARGE PRESSL~RE" as output option 3.

2. "BUBBLE CAP TE-IPERATLTIE" to replace "LINE PRESSLTIE AHEAD OF DISCHARGE VALVE" as output option 4.

3. Under item 4, the schedule of changes in operating conditions, the variable "PU!'IP RPM" is to be replaced by "SLTPLY ULLAGE PRESSL'RE". Figure 9A incorporates these changes and illustrates the way in which the hydrogen

programs interpret the input data entries . A template has been prepared which, when placed

over the screen of the graphic display unit, shows the correct meanings of the input display

entries with respect to the hydrogen version of "COLD FLOW,"

If desired, input variables may be examined and changed in the display hy the procedure

explained in Section 2.4 except in the table of nimbers showing time, valve opening, and

pump speed, where the vertical and horizontal cursors must be positioned before depressing

the space bar

.

Entry 1 allows a supply ullage pressure during transfer to be selected which may or may not be different from the ullage pressure during storage. (The storage pressure is

taken as that pressure which was selected previously under General Input Data.) Entry 1 along with entry 2 relates to the subcooling of the inlet liquid. This subcooling enters

into the calculation of discharge liquid temperature, or fraction of vapor being discharged.

Entry 4 allows for the selection of a schedule of changes in operating conditions. That

is, the supply ullage pressure or the discharge valve setting may be specified at six times.

Supply ullage pressure and valve setting change linearly' from one specified time to the

next. The program carries out the computation to ten seconds beyond the last entry in the

schedule.

The third entry under Cold Flow allows the selection of computed quantities to be

displayed. The desired quantities are selected as numbers 1 through 6. Striking ALT

MODE initiates the calculation, and the next display is the selected output graph.

3.3.3 Output

Typical output graphs are shown in figures 11 through 15 . The following variables

may be plotted as functions of time:

Fig. 11 Flow rate

Fig. 12 Total accumulated liquid discharged into the receiver after subtracting

off the quantity vaporized

Fig. 13 Receiver liquid temperature

Fig. 14 Bubble cap temperature

Fig. 15 Final vapor fraction

Fig. 15 Reriaining liquid volume.

13
OPTION 6 - COLD FLOW nh'^-ll^ 8.319

STEADY OPERATION AND TRANSIENT RESPONSE TO CHANGE IN OPERATING CONDITIONS

1. SUPPLY ULLAGE PRESSURE DURING TRANSFER IS 1.5 PSIG

(SUPPLY ULLAGE PRESSURE DURING STORAGE WAS SELECTED PREVIOUSLY)

2 . . INLET LIQUID WILL BE SATURATED AT CONDITION 1 1 - SATURATED AT STORAGE PRESSURE

2 - SATURATED AT TRANSFER PRESSURE

3. THE OUTPUT, FROM AMONG THE FOLLOWING, TO BE GRAPHED IS 1

1 - FLOW RATE VERSUS TIME

2 - TOTAL LIQUID DISCHARGED FROM THE PIPELINE VERSUS TIME

3 - PUMP DISCHARGE PRESSURE VERSUS TIME

4 - LINE PRESSURE AHEAD OF THE DISCHARGE VALVE VERSUS TIME

5 - OUTLET QUALITY VERSUS TIME

6 - FLUID DISCHARGE TEMPERATURE VERSUS TIME

4. THE SCHEDULE OF CHANGES IN OPERATING CONDITIONS:

:, MINUTES DISCHARGE VALVE FRACTION OPEN PUMP RPM

0 0.004 1.5

16 0.004 1.5

27 0.015 1.5

30 0.015 1.5

32 1.000 77.5

65 1.000 77.5

Figure 9. Option 6 - cold flow input display

.

OPTION 6 - COLD FLOW 03/31/75 9.884

STEADY OPERATION AND TRANSIENT RESPONSE TO CHANGE IN OPERATING CONDITIONS

1. SUPPLY ULLAGE PRESSURE DURING TRANSFER IS 1.5 PSIG

(SUPPLY ULLAGE PRESSURE DURING STORAGE WAS SELECTED PREVIOUSLY)

2. INLET LIQUID WILL BE SATURATED AT CONDITION 1 1 - SATURATED AT STORAGE PRESSURE

2 - SATURATED AT TRANSFER PRESSURE

3. THE OUTPUT, FROM AMONG THE FOLLOWING, TO BE GRAPHED IS 1

1 - FLOW RATE VERSUS TIME

2 - TOTAL LIQUID DISCHARGED FROM THE PIPELINE VERSUS TIME

3 - RECEIVER LIQUID TEMPERATURE

4 - BUBBLE CAP TEMPERATURE

5 - OUTLET QUALITY VERSUS TIME

6 - REMAINING LIQUID VOLUME VERSUS TIME

THE SCHEDULE OF CHANGES IN OPERATING CONDITIONS:

TIME, MINUTES DISCHARGE VALVE FRACTION OPEN TRANSFER

PRESSURE PSIG

0 0.004 1.5

16 . 0.004 1.5

27 0.015 1.5

30 0.015 1.5

32 1.000 77.5

65 1.000 77.5

Figure 9A. Option 6 - cold flow hydrogen input display.

14
Q2/Qiinb 10.014

100

•a: I—o

1 EQUAL PERCENTAGE

(PARABOLIC)

3 QUICK OPENING

(SQUARE ROOT)

PERCENT OF FULL FLOW

CHOOSE VALVE CHARACTERISTIC (1, 2, OR 3) J_

Figure 10. Option 6 - cold flow input display (continued).

03/31/75 9.884

STEADY OPERATION AND TRANSIENT RESPONSE

TO CHANGES IN OPERATING CONDITIONS

DISCHARGE TEMP AT A FLOW OF 12997 GPM WAS 36 R

15000 r- 3.24E+01

,

6.52E+01

,

1 .30E+04

1.24E+04

12000

9000

6000 —

3000

13.0 26.0 39.0

TIME IN MINUTES

Figure 11. Option 6 - output.

15

52.0 65.
500,000,—

400,000

300,000-

200,000-

100,000

32.0

CD

UJ£ 24.0

UJ

h-QI—

(

ZD

LU •O

16.0

8.0

STEADY OPERATION AND TRANSIENT RESPONSE

TO CHANGES IN OPERATING CONDITIONS

1 .68E+04

1 .27E+05

03/31/75 10.214

13.0 25.0 39.0 52.0

TIME IN MINUTES

Figure 12. Option 6 - output (continued).

03/31/75 8.699

STEADY OPERATION AND TRANSIENT RESPONSE

TO CHANGES IN OPERATING CONDITIONS

40 On- X = 7.31E-01, Y = 3.65E+01

X = 6.52E+01 , Y = 3.65E+01

65.0

1

13.0 26.0 39.0 52.0

TIME IN MINUTES

Figure 13. Option 6 - output (continued).

65.

16
03/31/75 8.812

STEADY OPEPJaTION AMD TRANSIENT RESPONSE

TO CHANGES IN OPERATING CONDITIONS

250 (- X = 8.12E-01 , X = 1 .22E+00,

Y = 2.20E+02

Y = 2.18E+02

oUJQ

200

150

100

CO 50

0.050

13.0 26.0 39.0 52.0

TIME IN MINUTES

Figure 14. Option 6 - output (continued).

03/31/75 8.995

STEADY OPERATION AND TRANSIENT RESPONSE

TO CHANGES IN OPEPJ\TING CONDITIONS

55.0

X = 8.12E-01

,

X = 1 .14E+00,

Y = 2.41E-02

Y = 8.04E-03

0.040

< 0.030

CO

t/5

I 0.02J

0.010

13.

G

25.0 39.0

TIME IN MINUTES

Figure 15. Option 6 - output (continued).

52.0 65.0

17
<:

o>

o

cr

LlJ DC

850,000

680,000

510,000

340,000

170,000

STEADY OPERATION AND TRANSIENT RESPONSE

TO CHANGES IN OPERATING CONDITIONS

03/31/75 9.164

X = 1 .30E+01

X = 2.60E+01

Y = 8.46E+05

Y = 8.39E+05

13.0 26.0 39.0

TIME IN MINUTES

52.0 65.0

Figure 16. Option 6 - output (continued)

18
4. Nomenclature

D = diameter.

D = external diameter of vent line,

e D. = internal diameter of vent line.

1

dSi = differential length of vent line.

dQ = heat flux to the hydrogen vent l:ne in the length dl. f^^ = Fanning friction factor calculated as though the total flow were liquid.

f^^ = Fanning friction factor calculated as though the total flow were vapor.

= liquid mass flow rate per unit cross sectional area.

G = two phase mass flow rate per unit cross sectional area,

tp

h = heat transfer coefficient between the outside of the vent line and the atmosphere,

e

h. = heat transfer coefficient between the inside of the vent line and the vent gas. h^ = average heat transfer coefficient for the double walled section of the vent line,

h^ = average heat transfer coefficient for the single walled section of the vent line,

k = heat transfer factor as defined by equation A^.

= k for the double walled section of the vent line,

k^ = k for the single walled section of the vent line.

= length of the double walled section of the vent line.

L2 = length of the single walled section of the vent line, m = mass flow rate,

p = absolute pressure.

(AP/Ax)^ = liquid pressure drop per unit length in the fill line.

(AP/Ax)^p = two phase pressure drop per unit length in the fill line. R = ratio of two phase to liquid flow rates.

R_ = value of R at the discharge end of the fill line.

T = absolute temperature.

= ambient absolute temperature.

T^^ = absolute temperature at the inlet of a section of vent line.

T = absolute temperature at the outlet of a section of vent line,

out

T = pipe wall absolute temperature. w

Quality, mass of vapor divided by total mass of the mixture.

6 = two phase flow properties parameter as defined by equation B4.

9 = two phase' pressure drop parameter.

= liquid absolute viscosity.

= vapor absolute viscosity.

= liquid density,

p = vapor density.

19
5. References

Boeing Company, Vehicle Vent Subsystem, Liquid Hydrogen Subsystem Launch Complex 39A

NASA P/N 75M05753, Test Report TR-520-D, Boeing Company (March 1, 1967).

Martinelli, R. C. , and Nelson, D. B. , Prediction of pressure drop during forced circulation

boiling of water, ASME Transactions, 70.> PP- 695-716 (1948).

Novak, J. K. , Cooldown flow rate limits imposed by thermal stresses in liquid hydrogen or nitrogen pipelines. Advances in Cryogenic Engineering, L5, Ed. K. D. Timmerhaus,

pp. 346-353, (Plenum Press, New York, N.Y. , 1970).

Supplement A. Oxygen Loading Simulation Computer Programs (1974). Available on request.

Voth, R. 0., Steward, W. G. , and Hall, W. J., Study of Cryogenic Propellant Systems for

Loading the Space Shuttle, Nat. Bur. Stand. (U.S.) NBSIR 74-366 (April 1974).

20
APPENDIX A

Vent Gas Temperature

The heat flux from the atmosphere to a differential length, di, of a cryogenic

ventline is

dQ = h (T - T ) IT D d£ . (Al)

e a w e The heat flux from the wall to the vent gas, assuming no temperature gradient through

the wall, is

dQ = h. (T - T) TT D.d£ . (A2)

1 w 1 (Symbols are defined in the nomenclature of this report.)

The vent gas temperature rise due to dQ, neglecting axial heat conduction, is

dT = 7— dQ. (A3) mc

P Elimination of dQ and T from equations (Al) , (A2), and (A3) yields, w

dT e e ^^^^ T - T / h D

a

/ \

If h^ and h^ are taken to be constant average values over the length L, integration

of (A4) yields.

D L

T - T = (T - T. ) exp (-k — ) (A5)

a out a xn m

where

TTh ^ (A6) /h D \

In the calculation of vent line temperature it is assumed that the heat transfer

from the environment to the vent line will have two characteristic coefficients. For the

double walled length, , of the vent line starting at the vehicle h = h^ and k = k^;

for the uninsulated length, L^, extending from the end of to the burn pond, h = h2 and

k = k^. Then, from (A5)

,

-k D L

T - T = (T - T ) exp ( ^ ^

), (A6)

a 1 a o

and

-k D L T - T = (T - T.) exp ( ^ ^

^ ). (A7)

a 2 a 1 m

T = Temperature at vehicle tank

o T^ = Temperature at the connection of and

T^ - Bubble cap temperature.

21
The exponents k and k were evaluated

Company [1967], Fig. 4-5):

T = 75 K (135°R)

o = 84.4 K (152°R)

= 281 m (923 ft.)

= 43.8 cm (17.25 in.)

T2 = 144 K (260°R)

= 344 m (1130 ft)

= 43.8 cm (17.25 in) T = 300 K (540°R) m = 1211 g/s (2.67 Ib/s)

k^ = 1.475 (10)"^

= 4.468 (10)"^.

Constant k^, k^ are used with equations (A6)

temperature (bubble cap temperature)

.

from the following experimental data (Boeing

and (A7) to compute the vent gas discharge

22
APPENDIX B

Two Phase Flow

In computation option 6, "COLD FLOW", heat leak into the liquid and pressure drop

along the fill line can result in vapor formation and two phase flow. The presence of even a small fraction of vapor in the fluid stream can cause a significant increase in

the friction pressure drop for a given mass flow rate. The correlation of Martinelli

and Nelson fl948] has been used to predict two phase flow pressure drop with good results

for all cryogenic fluids. An adaptation of that correlation has been used in this study

to predict the effect of the presence of vapor on liquid hydrogen flow rates. The modified

form of the Martinelli-Nelson correlation, given in equation Bl, has the advantage of re- ducing properly to the usual single phase expression for liquid or gas.

(«).-[

f Y^-^ f 0 (1-Y)^'^ -1 tv . tl ^ t Pv P£ J

2°

(Bl)

where the symbols are defined in the nomenclature of this paper. The two phase flow

factor, 9 is a function of liquid and vapor properties and quality (mass fraction of vapor).

e = 0(6)

0.056 , , 0.28 , , 0.5

(B2)

1 + ft) M

The experimentally derived relationship between 6 and 3 is shown graphically in

figure Bl.

The following equation, B3, fits the experimental curve 0(3) to within 5% of the

experimental 0.

2

0 = 0.8560 + 7.944e~-'-^"^^^^"°'^-' for 0 < 3 1 1 • (B3)

The value of B for hydrogen near 1 atm pressure is

(B4)

/i-v \^-^

1 + 0.380

For single phase liquid flow (Y = 0, 0=1) equation Bl becomes.

¥1

f ^ • (B5) 2D

The ratio of two phase-to-liquid mass flow rates for a given pressure drop per unit

length and given pipe size is then obtained from equation (Bl) and (B5)

:

23
0 0.1 0.2 0.3 0.4 05 0.6 0.7 0.8 09 1.0 ^, (Dimensionless)

Figure Bl. Modified Martinelli-Nelson two phase flow factor.

24
(B6)

In general single phase liquid flow will exist up to some point, L^, in the fill line.

Beyond the amount of vapor in the fluid stream will increase from 0 at to a maximum

at the pipe discharge. If we let the average value of R be defined as

G

and assume a linear variation of with X from L to L, we obtain

G s

^g = I[^gl(i-^)^ i^^r)] • (2«>

The enthalpy of the liquid increases with distance along the pipe due to heat

addition and the saturation enthalpy (or saturation temperature) decreases due to pressure

drop. The point at which saturation enthalpy equals the fluid enthalpy determines the

saturation point L which is required in equation (B8) . We obtain,

L E. - E.

s _ is in

L ~ E. - E. + E ^ IS in out

All of the enthalpys on the right side of equation (B9) are calculated in the cold flow

program. These enthalpys, however, are a function of the flow rate which in turn varies

with the exit quality. Therefore, an iterative solution becomes necessary for the two phase flow ratio:

1. From the initial (assumed single phase liquid flow rate) the enthalpys are calculated for equation (B9)

.

2. R from equation (B8)

.

G

3. m from (B6)

.

The calculation returns to step 1 and steps 1 through 3 are repeated until the final

calculated m is within 0.1% of the assumed value,

tp

— . (B9) OS

25
APPENDIX C.

Loading of the Minicomputer

The method of loading programs into the minicomputer is described in Section 3.3

of the instruction manual. This appendix is an elaboration of the procedure described

there.

The Binary Loader

The binary loader is usually in the minicomputer and is not destroyed by any of the

programs. For that reason, following the procedure below should be sufficient to load

any program in the minicomputer.

However, occasionally a sharp spike on the power lines or a malfunction of the memory

in the computer can cause the binary loader to be destroyed. If this should happen, the

"Bootstrapping" procedure must be performed first.

1. Preparing the Teletype

The minicomputer and CRT display must be turned on but not running and the CRT display

LOCAL/LINE switch set to LOCAL. The teletype is plugged into the back of the CRT display.

Turn the teletype power switch, LINE/OFF/LOCAL, to LINE. With the teletype reader switch

in OFF position, place the paper tape containing the program in the reader with the tape

coming out toward the front of the teletype and the narrower side from the sprocket holes

in the tape toward the outside of the teletype. Position the tape so that unpunched tape

is over the read position. Set the reader switch to ON.

2. Loading the Program

On the minicomputer, the upper row of switches is called the Switch Register, and

are labeled 0 through 15. The lower row of switches are all momentary switches used for

control and their functions are listed on the panel.

Set the Switch Register 0, 1, 2 down and 3 through 15 up. Press control switch RESET

and then START. The teletype should start reading paper tape. At the end of each binary

block on the tape, the printer mechanism should receive some null character and, thus,

cycle or "chuckle". Should it fail to do this, back up to the beginning of the paper tape

and try again. Should it still fail it may be necessary to follow the "Bootstrapping"

procedure and then try again. If the program loads correctly, it may self start or it may

halt the computer. If the computer halts, set all the Switch Register switches down except

14, which must be up, and press START. If subsequent operations are to be between the

minicomputer and the CRT display, the LOCAL/LINE switch on the CRT should be set to LINE

before pressing START, and the teletype turned to OFF,

If the computer halts in the middle of the tape reading, the teletype has made an error while reading the tape. It is not necessary to start the tape over completely.

Merely back the tape up at least one block and start the computer again. The beginning

of a block is fairly easy to recognize. It consists of two frames with no punches in the

tape except the sprocket hole followed by a frame with at least the four top most positions

punched followed by a frame with all positions punched. Reposition the tape on one of the

two unpunched positions, set the teletype reader to ON and push START on the minicomputer.

If the teletype fails to start "Chuckling", the tape should be restarted at the beginning.

Bootstrapping

It may occasionally be necessary to restart the minicomputer from a completely

obliterated condition. To do this, turn on the minicomputer and the CRT display. Set

the CRT display LOCAL/LINE switch to LOCAL. Prepare the teletype with the tape marked

"CHUCKLING LOADER" in the reader just as you would for any other program tape. Next,

follow the instructions in TABLE C-1. After the last line of the table has been executed

the computer should read the tape and stop at the end. It will not "chuckle" the teletype.

If it does not read the tape, the computer or teletype is likely in need of repair. If

it does read the tape correctly, proceed to load program as described in the section,

Binary Loader.

26
XI

CO w

cn z = z

(Uu W H H H

z

M

M M M

(/I c o o O

0) Ph w w w

H w o Q : Q

o

•a

a

3

iHSQQSO OOC3QO

OPDQSQ QOQ3Q

O

dJ .—I

TO H

c

o

•H

-U •H

COO

XiO

4J •H

!-l

00

paou

•H

w

lU QQQQ Q 3

27
APPENDIX D Hydrogen Computer Programs

Program CDT

Option 3. Cooldown Time

Due to the length and complexity of the program, a computer flow diagram

and list of computer symbols are included.

20-190

Read data

I 200-350

Initializing and

re-naming of variables

I

360-510

Calc VUL, 02TL, XLT, XTV, PP, TXL, DUV, XLX

I

. 520-710

Initializing, converting units

I

720-760

Calc AW, AFL, AFS, AWL, AWS

DHWL = 75.55

DENWL = 7.88

(Stainless steel) neg pos

DENWL = 75 55 DENWL - 8 90

( Invar

)

DHWL = 157.15

DENWL = 2.699

(Aluminum)

DHWS = 75.55

DENWS = 7.88

(Stainless steel)

neg pos

DHWS = 75.55

DENWS = 8.90

(Invar)

DHWS = 157.15

DENWS = 2.699

(Aluminum)

970-1010

Calc PUP, PG, PP, PSTM

1040*

CALL HITRAN

HCRD

(Bare pipe)

1050-1080

Calc or set value KKK, NPCY, TEND

YES NPCY = 2 (Pump started)

28
NP.LE.O. AND. N0PT.GE.3 YES

(Pump does not

exist and pump

AP has been

requested)

© "WITHOUT A PUMP

THERE IS NO PRESSURE DROP"

I zz:

CALL CDT2FILE*

I

No output possible

NO

1110-1150

Calc C2, D0D5, D0D51, XI

YES 1190

Calc FXOD

(Increment longer

than distance to

size reduction)

1200-1220

Calc XPDW*, PR, XUGI*

1240

lOOODO 5U I = ISTART-IEND

1250-1260

Calc XI, FLEN

YES Calc PUP

1280

Calc XPDW'^

29
NO

GO TO 52

YES

1320-1370

Calc XOD, AW, DENW, DHW, XI, AFL

1390

Calc XOD, AW, DENW, DHW, XI,, AF

1470

Calc F, FXOD, PC, C6

^""mo^ .^^^

^,^NI . LT O,,^-^-^

Call HTTRAN* HCRD

YES

30
1900-1940

@ Calc PR, UGIF*, UG, UIN, UID

1550-1590

Calc C3, C4, UGIF*, UFIT, C7

1960-1990

Calc UCI, UCLUl, DP

YES

1600

D026 K = 1, 15

1610-1840

Iteration for interface

gas velocity, liquid velocity and interface velocity

NO

yes -|

(velocity within

tolerance)

26) continue

YES

1

1870

Calc Ul, DP

JL

2130-2270

Calc I START, lEND, T, DP, FLEN, QQ, XI

pos

to

Q,GE.1.0E+04_;>— YES - Q=1.0E+04

2290

Calc I END , XMASSG,

XMASSL

PRINT "WITHOUT A PUMP

THERE IS NO PRESSURE

DROP"

Return to

start of

DO loop

i

to 1000

2050-2090

Calc XMASSG, XMASSL, IT, T, UPROPP

to 1000

50 continue

(end of DO loop)

I < TEND

Return to

start of

DO loop

I > lEND

Exit from DO loop

CALL CDT2FILE

(Plotting of results)

31
CDT - Computer Listing Symbols

AF Flow cross section area, cm

2 AFL Flow cross section area, large pipe, cm

2

AFS Flow cross section area, small pipe, cm AW Cross section area of the wall at the current liquid-gas interface

2 location, cm

2

AWL Cross section area of the wall, large pipe, cm

2

AWS Cross section area of the wall, small pipe, cm

CI Constant used to convert liquid velocity to pressure drop due

to the pump

C4 Total heat transferred through uninsulated line to liquid, watts

C6 Same as C7 except reciprocal

e7 AF/AFL-used to correct velocity calculation for area

3

DENG Density of the gas at the liquid-gas Interface, gm/cm

3

DENL Density of the liquid, gm/cm

DENW Density of the wall material at the current liquid-gas interface,

gm/ cm"^ 3

DENWL Density of wall material, large pipe, gm/cm

3

DENWS Density of wall material, small pipe, gm/cm

DHL Change in enthalpy from liquid to ambient temperature gas, Joules/gm

DHW Change in enthalpy at the current liquid-gas interface location,

Joules/gm

DHWL Change in enthalpy, large pipe, Joules/gm

DHWS Change in enthalpy, small pipe, Joules/gm

DIAIL Large diameter before reduction, in-cm

DIALS Small diameter after transition, in-cm

DIAOL Outer diameter of the large pipe, cm DIAOS Outer diameter of the small pipe, cm

D0D5 (DIAIS/DIAIL)^

DP Pressure drop across the pump at a particular time during cooldown,

psi

DPP Reference pressure, psi

DUl Constants used during an iteration calculation; difference between

a trial velocity and a calculated velocity, cm/sec

DTJ2 Same as DUl

DX Length increment, cm .

32
2. CDT

F Friction factor

FLEN Total length of line cooled, cm FLOW Flow rate, gpm

FXOD Friction factor times the gas column length divided by an effective diameter

2 H Surface heat transfer coefficient, watts/cm

HMAX Maximum length cooled without running the pump , cm

lEND Number of DX increments required to traverse entire length of

pipe to be cooled

II Used to count number of DX lengths calculated

MU Wall material for a uniform pipe size

MWL Wall material before transition

MWS Wall material after transition

02TL Supply liquid level, ft

NI Existence of vacuum insulation, 0-yes, 1-no

NOPT

NP Existence of pump, 0-no, 1-yes

NPCY Indicates whether pump has started, 1-no, 2-yes

NPS Pump free wheeling-0, started after PSTM-1

NV No. of the discharge valve which is open

NVR Existence of vertical rise, 0-yes, 1-no

PG First value of pressure in iteration, psi

PGl Supply pressure, psi

PMAXL Maximum length cooled when pump is running, cm PMAXP Maximum liquid driving pressure when the pump is running, psia

PP Reference pressure, psi

PR Pressure ratio across the gas column in the pipe

PSTM Pump start-up time, min

PUP Upstream pressure acting to push liquid into pipeline, psia

PDWF An external function used to calculate a pressure due to a head

vise

PDWN Pressure at the liquid-gas interface; is equal to upstream

pressure minus a head due to any vertical rise

33
3. CDT

Q Flow, gal/min

QPP Print out of initial flow rate, gal/min

RE Reynolds number

RELHU Relative humidity, percent

RPM Pump speed after it is started, RPM

T Time in interation loop, sec TAMB Ambient temperature, deg F

TIP Print time, sec U Liquid-gas interface velocity as it moves down the pipe, cm/sec

UCI Velocity of liquid vapor interface, ft/sec

UCL Velocity of liquid determined by boil-off gas, ft/ sec UFIT A constant to fit the gas velocity versus pressure ratio

UGI Gas velocity at the interface, cm/sec

UID Denominator in expression for UCI

UIN Numerator in expression for UCI

UL Liquid velocity in pipe due to pump pressure drop. cm/ sec ULLP Ullage pressure, psig

UPI Uniform pipe inside diameter, in-cm

UPWT Uniform pipe wall thickness

WIND Wind velocity, knots

WTL Wall thickness before transition, in

WTS Wall thickness after transition, in

XCL Length of line to be cooled, ft

XFINAL Final length, cm

XL Total length of line, ft

XLT Length before size reduction, ft

34
4. CDT

XLV

XOD

XTV

XI

Function

CDS

CDXMAX

HTTRAN

PDWF

UGIF

Length to vertical rise, ft

Gas column length divided by an effective diameter

Length of pipe before vertical rise, ft

Liquid column length, cm

Subroutines

Maximum cooldown length, ft

Return heat transfer coefficient, Btu/lb°F

Return liquid-vapor interface pressure

Used to calculate gas velocity in the gas column supplied an FXOD, and a pressure ratio

35
" Program TS Option 1, Thermal Stresses

10 DIMENSION P(12)

20 DItlENSIOfI XL(9) ,D(9) ,H(2)

30 DATA P/32. 29,-0. A254, 261 . 8, -3. 104, 130A. ,-11 . 2,

4 0& 0. 334,-0. 348, 2. 154, -2. 86, 10. 87, -10. 731/

50 READ: PFID, POn, PFO0,MF

I-l

IF(HF.GT. 1) 1-7

TOD" (PFOD-PFIO) / ( 2 . 0*PFin)

C 1=P( I) *EXP( P( I+l ) *T0n)

C2=P( I+2)*EXP(P( 1+3) *TOD)

C3=P(I+4)*EXP(P(I+5)*TOn)

V;ilAX-PFIIi*(Cl+C2+C3)

V;ilIN = 0. 00661 442*PF 10**2+0. 02 21 9435*PFID-0. 01 8808 7 7 GP!IL = WMAX*101 . 6

60

70

80

90

1 00

110

120

130

140

1 50

160

170

180

190

200

210

2 20

230

240

2 50

2 60

2 70

280

nP!lS = WMIM*l 01 . 6 PRIMT:"&"

DO 9 1=1,9

9 PRINT:" " PRiriT

PRINT

PRINT

P!? INT

PRIMT

PRINT

PRINT

PRINT

PRINT

END

'THE MAXIMUM FLOV; PERMITTED V;iTHOUT CAIISIMG EXCESSIVE THERMAL

'STRESS IS ",GPML," GPM"

'THE MINIMUM FLOV/ PERMITTED V/ITHOUT CAUSING EXCESSIVE THERMAL

STRESS IS ",GPMS," Cl'Ul,

Program CDT Option 3, Cooldown Time

10

20

3 0 AO

50

f.0

7 0 ^0

n 0

1 on

1 1 n

1 ? 0

1 3 0

1 LO

1 "^0

1

I)

1 70

1 HO

1 9 0

? 0 0

1 o

?. >. 0

2 7 1!

2 'tO

2 5 0

? fS 0

2 70

'JSE CDTSUH ;PL0T :CDT2FII,E

C0^tM0N DHL, TAMR, RELHU, D I AI L , DI A I S , D I AO L , DI AOS , AFS , AFL , TXL , XC L , XLT

COMMOfl XLV, XT V, WIND, KKK, H, DVV, AW

COMMON XL(9) , D(4 )

, HH( 2) , HTOR , XMASSL, XMASSG, PSTM

COMnnri FLEN( 105) ,T( 1 05) , 0( 1 05) ,DP( 105) ,NP, NFS, NOPT, lEND

nilKns IO!I UL(2) ,UCL(2)

nillKNSIOt! XXL(9) ,Dn(7)

AD: (rXLd) , 1=1 , 5)

iir-'- : ( xxi.ri ) , 1 = ^1

, 9) , nn( 1)

'

P.-^-AO: f DD( I) , 1 = 2 , 6)

K r.AD : DO ( 7 ) , GALR , VNT , f! 1 , GP^! DO 2 00 J= 1,7

?oo iF(nD(j).LE.n.i)nD(j)=o.i

PUMP, SPn, ULI,P, SVOL, 01

n V

•!\;T,, M'JS , M\/6 , M",/7 , MU8

•"./'j,v;tl,i?ts,ut6,',;t7

'„'tr,',jt", xcl, mp.nps . PSTM , R?:i , no PT

-.n( 1 )

'I ; A 0

'-:a 0

n i". A D

!; ?. A 0

i; p A ;i

;i K A ")

:

'U * I I, nn ?oi ,1 = 1,3

;i ( J ) = :^ n ( I

)

201 YT.f j)=xxi,f 1) /3.

iM 3 ) = P 0 ( 2 )

!^ Hi 1 = T ( 3 ) aL r A ) = ;'xi, ( 2

)

DO 2 02 ,T = 5,y

36
Program CDT Page 2 280 D(J)=DD(3)

2 90 2 02 XL( J)=XXL(3) /6.

3 00 HH ( 1

) -XXL ( 3) / 6

,

310 HH(2)-XXL(3) /6,

320 TAIIB = 85.0

330 WIND-IO,

340 RELHU=80.

350 CAP=900000,

360 RSPn=0, 62035*CAP**0. 33333

370 vul=cap-svol

3«0 02tl-2.*rsph-0. 477465*vul/ (rsph*rsph)

390 i;tob = i 400 xlt=xl ( 1 ) +xl ( 2 ) +xl ( 3 ) +xl ( 4

)

410 xtv=xlt-xl(4)

420 PP-(-3. 782475 + 0. 012^81 3 3 5*RPM + n .26 1 0 A 5 9 E -3 * RPM* RPM) *n . 49 4 4 01 430 IF( MTOB , r,T . 2) no TO 40

440 TXL = XLT+XL(5)+XL(7)+XL(8)+XL(«?)+HH(1)+HH(2)

450 r)VV=(D(7)+n(8)+n(9) ) /3.0

4 60 XT,X=XI, (7)+XL(«)+XL(9)+UH(l )+Hn(2)

4 70 GO TO Al

4 80 4 0 TXL-XLT+XL(5)+XL(6)

490 nvv-n(6)

5 00 XLX=XL(6)

510 41 CONTINUE

520 DIAIS=D(5)

530 XMASSG=0.0

540 X1IASSL = 0.0

550 PI=3. 141 592654

560 DENL-O. 07080

570 TXL-TXL*30. 48

580 XCL-XCL*30. 48

590 XLX=XI,X*30. 48

600 XLT-XLT*30. 48

610 IF(XCL.GT.TXL) XCL-TXL

620 ISTART=1

630 FLRr:(l)=0.0

640 TFINAL=0.0

650 XFI^!AL = 0,0

660 PVV=nvv* 2. 5 4 670 DIAIL=niAIL*2 . 54

680 niAIS=niAIS*2 . 54

690 IF ( nvv. GT . DIAIS ) DVV=niAIS

700 niA0L = riIAII,+5 . 0 8*i;TL

710 niA0S=DIAIS+5 . 08*UTS

720 AVV = PI/4, o*r)vv*nvv

730 AFL = oi/4, 0*niAIT,*niAIT,

7/,n AFS = PI/4. 0* TTAi?;*ni \TS

7Sn Aw'I, = PI/4. 0*( niAOT,**2-niAII.**2)

76 0 AV.'S = PI/4. 0*(niAOS**2-niAIS**2)

77') Cl = 115«4,0

7^(> nH.I. = 44 56 .1

7^1) IF(.'!V;L-2) 5,6,7

•^ni' 5 ni!'./I.= 75. 55 fin n(:r;wL=7.8 8 «2n GO T?) s S30 6 0'!UL=157.15

«40 n':N",'L=2 .699

S5n GO T'l H

.''6(' 7 DKUL=75.55

^'•7'> niIi4i/L = >S . 9"

PH(I « IF(Ml'S-2) ^ , H', 1 1 fin 0 nHWS=7 5.53

ynn nfHfS=7.8«

37
Program CDT Page 3 910 GO TO 12

920 10 BIIWS-157.15

930 nENl7S-2.699 - 9A0 GO TO 12

950 11 DHWS-75.55

960 DENWS-8.90

970 1 2 PUP-02TL*0. 03069+ULLP+U, 696

980 PG-PUP

990 PGl-PUP ' 1000 PP-PP+PGl

1010 IF (NP.EQ.O.OR.NPS.EQ.O) PSTM-l.ElO

1020 H-0.0

1030 KKK-1

1040 IF(NI.EQ.l) CALL HTTRAN(60,0) - . 1050 KKK-2

1060 IIPCY-1 . ^ 1070 DX-XCL/97

1 0 80 IEMD-98

1090 IF(NPS.EQ, l.AND.NP.EO, 1) NPCY-2

1100 IF( (NP.LE.O) .AND. (NOPT.GE, 3) ) GO TO 79

1110 56 C2-3. 0086E-03/ (TAMR+460. 0)

1120 T(1)-0.0

1130 r)OD5-(DVV/DIAIL)**5.0

llAO DOn51-(DVV/DIAIS)**5,0

1 1 50 Xl-DX/2.

0

1160 IF(X1,GE.XLT) GO TO 14

1170 FXOD-( (XLT-Xl) *D0D5+(TXL-XLT-XLX) *D0D51+XLX) *0. 02/DVV

1180 GO TO 15

1190 14 FXOD-0.02*((TXL-Xl)*nOD51+XLX)/DVV

1 200 1 5 CALL XP0W(X1 , PDV;F)

1210 PR-(PUP-PDV/F) / 1 4. 696

1 220 CALL XUGKPR, FXOD, UGI) • 1230 X1--DX

1240 inOO DO 50 I-ISTART, lEND

1250 X1=X1+DX

1260 FLEN(I+l)«FLEN(I)+DX/30.48

1270 IF(T(I) .GT.PSTM) PU P= P P- 5 . 9 6 0 6 3 6 E-8 * OPP*0 P

P

1 280 CALL XPDV/(X1 , PDl/M)

1 290 IF( ( PUP-PnVJN) . LT . 0. 0) GO TO 52

1 300 r)EN0=(PUP-PDV;N)*C2

1310 IF(X1,GE.XLT) GO TO 2 0 132 0 XOD=( (XLT-Xl ) *D0D5+(TXL-XLT-XLX) *D0D51+XLX) /nVV

1 330 Al/ = AWL

1 340 D[:m? = DENWL

1 350 nHW = DHV;L

1 360 XI = PI*niA0L*Xl

13 70 AF=AFL

13 HO GO TO 2 2

1 390 20 X'0n=( (TXL-X1-XLX)*D0D51+XLX) /DVV

14 00 AW = AW

S

1410 ni:in;=DEMWs -

. 1420 D!IU = nHUS

1430 XI = PI*( (DIAnLAXLT) + (Xl-Xy/r)*DIAOS)

1A40 AF=AFS

1 450 2 2 lli:=ll 1 61 .*DEMG*UGI*DIAIS

1460 IF( Rf;. LT. 3. 0E3) RE=3.0E3 , -

1 465 H1IF = 1 01 , 6/DIAIS

1466 IF(RHF,GT . 60.) RUF=60.

1 4 70 F = 0. 00 5 5*( 1 . 0+(RMF + l ,E6/RE) **0 . 33 3 33)

14«n FXf)D = XOD*F

1 490 PG=-0 . 02

15(10 Cr-, = AVV/AF

1510 IF(flI.LT. 1) GO TO 2 4 - -

38
Program CDT Page 4 1520 CALL HTTRAM(T(I)*60.0)

1530 24 IF (NP.EQ.O) GO TO 36

1540 IF(T(I) .GT.PSTM) GO TO 36

1550 C3-AF*DHL

1560 C4-H*XI

1 570 CALL XUGI ( 1 , 1

, FXOD, UGIF)

1580 UFIT-UGIF*C6/0.

1

1590 C7-AF/AFL

1600 no 2 6 K-1 , 1

5

1610 KK-K

1620 DO 71 IK-1,2

1 630 IF( PUP-PDV/N-PG) 28, 28, 30

1 640 28 PG-PUP-PDV/N

1650 UL(IK)-0.0

1660 GO TO 33

1 670 30 UL(IK)=S0RT(C1*(PUP-PDV;N-PG) ) 1680 33 DENG-PG*C2

1690 PR-PG/14.696

170 0 IF(PR.GT. 1, 1) GO TO 7 2 1710 UG»UFIT*PR-UFIT

1720 GO TO 73

1730 72 CALL XUGI ( PR , FXO D , UGI F

)

1740 UG-UGIF*C6

175 0 7 3 IF(PR,LT. 0. 0) UG=0.0

176 0 UCI-( (UG*DENG*C3) -C4) / (C5+(DENG*C3)

)

1 7 70 UCL(IK)-(IICI + DENG/DENL*(UG-UCI) ) *C7

1780 PG=PG-0.01

1 790 7 1 COIJTINIJE

1800 DU1-UL(1)-UCL(1)

1810 DU2=UL(2)-UCL(2)

1820 IF(ARS(DU1) ,LT. 0.001) GO TO 34

1830 PG=PG+0.0 2-nUl*0,01/(DUl-DU2)

1840 UGI=UG

1850 26 CONTINUE

186 0 GO TO 5 2 1870 34 H1=1.0/UCI

1 880 DP(I)=PlJP-PnHN-PG

1'"'0 IF(!'l) 5 2 , 5 2 , 3 P.

1 900 36 PR= (PUP-Pnv;i!) / 1 4 . 696

1910 CALL Xll(;i(PR, FXOO, UGIF)

19 2 0 ur. = UGIF*C6

10 31) n I M= ( U G* DE NG* AF* DHL ) - ( H * X I )

1

'< 4 0 u 10= ( n E AU* D li'.; ) + (

n

e m g* af* phl ) 195 0 I F (Ulrl. LR . 0. 0) GO TO 5 2 196 0 1!C I = UI.1/Uin

19 70 l'CL( 1 ) = (UC I + HEMG* ( HG-UC I ) ) *AF / AFL

it))!o 1! 1 =ui n/m •; I'i'Ml D P ( I ) =PG 1 -PUP

2001) IF ( UCL( 1 ) . GT . 0. 0) GO TO 3 8

2 0 10 GO TO 5 2 2020 38 O ( I ) =AFL*60. 0*Uf;L f 1 ) / 4 546 . 1 203 0 IF(0(I) .GT. l.E+4) n(I)=l.E+4

21^40 >; I i A S S G = X: ! A R S G + n £ ;j G * A F * U G * 11 1 * 0 X 2050 XIlASSL = X!lASSL + nEML*AF*UC L ( 1 ) *Ul*nX

2 0 6 0 I I = I

2 0 70 T n + 1 ) =T ( I )+H l*nX / 60 . 0

2f)H() iip;^ = {il 2 on 0 n p p = o ( 1

)

2 1 00 5'i Cn.tlTi'HfE

2110 GO TO 100

2 1 20 5 2 IF( iiPCy . EO. 1 ) r,0 TO 100

2 130 ISTART=I IJ-3

2] 40 iK;in=i'-:ni+3

39
Program CDT Page 5 2150 T(II+1 )-T(II)+n, 001

21ft0 T(II+2)=PSTM-0.001

2170 T(II+3)-PSTM+0.001

2180 DP(II+1)=0,0

2190 DP (I 1+2) -0, 0 2200 FLEN(II+1)-FLEN(II)

2210 FLEN(II + 2)=-FLEN(II) <

. - 2220 FLEN(II+3)«FLRN(II) , 2230 0(II+l)-XI*H/(nHL*nENL*75. 76833)

2240 0(II+2)»0(II+1)

2250 X1=X1-DX

2260 NPCY-1

2270 no TO 1000

2 2 80 100 COHTINUE

2290 IEND=II

2300 XMASS(; = XMASSG/453, 59

2310 XIIASSL = XMASSL/453 . 59

2320 79 PRIi'^T : "WITHOUT A PUMP THERE IS NO PRESSURE DROP//

2330 CALL CDT2FILE

2340 END

Subroutine CDT2FILE

Graph Headings and Labels for CDT

10 SlIRROUTINE CDT2FILE

2 0 COMMON DHL, TAMR , R E L H U , 0 1 A I L , D I A I S , D I AO L , D I AOS , AF S , AFL, TXL, XC L , XLT

30 COMMON XLV, XTV, WIND, KKK, H, DVV, AVV

40 COMMON XL(9) ,D(9) ,HH(2) , NTO B , XM AS S L , XM AS S G , PS TM

50 COMMON FLEN( 1 05) ,T( 1 05) , 0( 1 05) , DP(1 05) , NP, NPS , NOPT, lEND

60 ASCII Al (42) , A2 (1 4) , A3( 1 4) , Bl( 1 4) ,CC1 ( 7)

7 0 T(IEND+l)-T(IENn)

8 0 T(IEND+2)=0.

0

9 0 ENCODE ( Rl , 75)

lf)0 75 F0RMAT( 20X, "TIME IN M I NUTE S

"

, 2 1 X

)

1 I n ENCODE ( A3, 55)

120 55 FORMAT(56X)

130 IF (NP-1) 61,62,62

140 6 1 ENCODE (A 2, 77)

150 77 FORMAT( 1 3X, "THERE IS NO PUMP IN THE SYSTEM", 13X)

160 GO TO 5 6

1 7 0 6 2 IF ( N P S - 1 ) 6 3, 64 , 64

1 KO 6 3 ENCODE ( A2 , 79

)

190 7') FORMAT ( 4X, " THl>ar A FREEWHEELING PU1?P DURING THE ENTIRE PERIOD", 3X)

2 00 CrO TO 5 6 21 0 6A I PSTM=PSTM

2;>0 CNCODE (A 2, 76) IPSTM

9 M) EOflMAK 1 1 X, " HNT 1 1, PUMP STARTS /kT",I6," M I M NT K S

"

, 1 1 X ) 2 40 5r, CdNXriHE

,'50 ii!L = x:iAssr,

I i(; = XMASSG

2 70 IK (tinpT.Ro.?.) ENCOni: (A3,6S) IML,IMG

Tyc f,5 I'DKllMC' TOTAL LTOHir) I N FLOW" , T , " LP.S, TOTAL VF.rlT",I6," LBS ")

?'io f:::f;o)iF ( ai , 2^ ^?,

3 00 2 E0R>;AT(" LIOIIII1 l^ PRIVEN RY MLLAGE PRESSURE AN't STATIC HEAD

310 IH- (iJopT-?) «1,«2,83

?'M) P-l FLi:N(IEND+1 )=FLEN( lEND)

3 30 Fy,E'!( I

- •!n+?)=0.0

14" Eiiconi: ( CC 1 , 74)

3Sr, 7/, FdKOAT r 6X, " LEN'rr 11 COOI.RP ET",6X)

40
Subroutine CDT2FILE Page 2

3f>0 CALL r,RAPH( Al , Bl , CCl , lEND, T, FLEN)

370 GO TO 85

380 82 IEHD-IEND-2

390 T ( IEND+1 ) =T ( LEND)

4 00 T(IEHD+2)-0.0

410 Q(IEND+1 )-0(IENn)

420 Q(IEMD+2)-0.0

430 ENC0DE(CC1 , 78)

440 78 FORMAT (7X,"FL0U RATE GPM",8X)

450 CALL GRAPH ( A 1

, B 1

, C C 1

, I E M D , T , Q

)

460 GO TO 85

470 83 DP(IEND+1 )=DP(IEMD)

480 ENC0DE(CC1 , 48)

490 48 F0RMAT(6X,"PUIIP DELTA P PSI",6V)

500 DP(IEMD+2)-0.

0

510 CALL GRAPH ( A 1

, R 1

, C C 1

, I K N D , T , D P

)

520 85 COMTINHE

530 RETURN

540 END

Subroutine CDTSUB Page 1 Heat Transfer and Pressure Drop Subroutines for CDT

5 SUBROUTINE HTTRAM (TIME)

1 0 COriMOfl DHL, TAMR , REL H U , D I A I L , D I A I S , D I AO L , DI AO S , AF S , AFL , T XL , XC L , XLT

15 COMMON XLV, XTV, WIND, KKK, HCRD, DVV, AW

20 C0M!!ON XL(9) ,D(9) ,HH(2) ,NTnR

300 DAVG=(DIAOL+DIAOS) /2.

310 HCRD-1 . f)846/ (DAVG**0. 25)

330 RETURM

33 5 END

340 SUBROUTI'IE XP DU ( X 1 , PDU F)

345 COMMON DHL, TAMB , RELH U , D I A IL , D I A IS , D I AO L , D I AO S , AF S , AF L , T XL , XC L , XLT

3 5 0 COMMON XL V , XT V , \1 1 J D , KY. :'. ,

'-1 . D V V , AV V 35 5 COMMON XL ( 9 )

, D ( 9 ) , HH ( 2 ) , NTOR

3^0 X=Xl/30.48

3 65 CONV = 0 . 030fi9 4

3 70 IF(X.GT.XTV) GO TO 5

3 7 5 ?Dv7F=-0.0

3 8n r?:tiir:,' 3>^5 5 IF(X,GT. (XTV+XLC4)+XL( 5) ) ) GO TO 10

390 Pnv.'F= (X-XT V) *CnNV

395 RETURN

400 10 IF( NTOR . EO. 2) GO TO 15

4 05 IF( X. GT. (XTV+XL(4)+XL( 5 )+XL ( 7) ) ) GO TO 2 0 410 15 ^m'V= ( XL (4)+XL ( 5 ) ) *CONV

i 1 5 ^ T I ! K :

:

420 20 IF(X.GT. (XiV+XL(4)+XL(5)+XL(7)+HU(l ) ) ) GO TO 25

A25 "l)UF=(X-XTV-XI.( 7) ) *CO.'IV

4 3(1 11 RTURN

435 2 5 IF( X, GT. (XTV+XL ( 4 )+XL ( 5 )+XL ( 7)+HH( 1

) +XL ( 8) ) ) GO TO 3 0

4 4 0 PD;/F= (XL ( 4 )+XL ( 5 ) +1' 1! ( 1 ) ) * C 0 -I v 44 5 IF.TUR;

4 50 3 0 IF(X.GT. (XTV+XL(4)+XL(5)+XL(7)+'^H(I)+XL(>^)4-;!H(2) ) ) GO TO 4 0 455 IHTHRN

4 6 0 AO POV-'r =XL^'*COrTV

Aiss iihTUR:;

4 7 5 siiHrroMT I""-: xugi ( x, fxo , ugif)

41
Subroutine CDTSUB Page 2 480 IF(X,GT. l.O.AND.FXnni.GT.0.0) GO TO 10

485 UGIF-0.0

490 IF( FXOLI. LE. 0. 0) UGIF-1 . 340E05

49 5 RETURN

500 10 PR-X

505 S0II02 = 1 . 340E05

510 CHN»S0RT(6. 25+6. 0/ (PR*PR) ) -2 . 5 51 5 FXOD-FXODI

52 0 FLOnCH»(l . 0-CHN) / ( 1 , 4 * C HM ) +0 . 8 5 7 1 4* ALO G ( 1 , 2*CHN/ ( 1 . 0+0, 2*CHN) ) 525 IF(FXOD.LE.O.O) FXOD»0.1E-8

530 IF( FXOD.LE. FLOOCH) GO TO 45

535 GM2=0.7142ft*(1.0-1.0/(PR*PR) ) / ( FXO D-0 , 85 7 1 4* ALOG ( 1 . 0/ (PR*PR) )

)

540 F2=1.0/GN2

545 DO 44 IITRY«1,50

550 GM3='SQRT(6,2 5 + 5.0*(PR*PR)*GN2*(1. 0+0, 2*GN2) )-2. 5

5 55 F3-1.0/GM3

560 FXODT-0, 7 1 4 2 8* ( F2-F 3 ) +0 , 8 5 7 1 4* ALOG ( ( F3+0. 2) / ( F2 + 0. 2)

)

565 ERR=FX0D-FX0nT

570 rF(ABS(ERR/FX0D) ,LT. 0,001 ) GO TO 80

5 75 DF3r)F2«»( F2 + 0. 4) *( F3 + 0, 2) *F3 / ( ( F 3+0 , 4 ) * ( F2 + 0 . 2 ) * F2

)

580 nER»0.71428*(l,0-DF3nF2)+0,85714*(DF3DF2/( F3+0, 2)-l ,0/ ( F2+0. 2)

)

585 F2-F2+ERR/ OER

590 GN2»1,0/F2

595 44 COtlTIMUE

600 PRir]T:"VGl DID NOT C 0 H VE RGE #

"

, X , FXO D

I

60 5 GO TO 80 • 61 0 45 GM2-1 . 0/ ( 0. 965* ( FXOD**0 . 5229 ) + l . 0)

615 GH2=GM2**2

62 0 F2=1.0/GN2

625 F3=l .

0

630 DO 70 ITRY=1,50

63 5 FX0DT = 0 . 7 1 4 2 8 * ( F 2 -F 3 ) +0 . 8 5 7 1 4 * ALO G ( ( F 3 + 0 , 2 ) / ( F2 + 0, 2) ) 640 ER[1 = FX0D-FX0DT

645 IF ( ARS (ERR/ FXOD) , LT . 0, 001 ) GO TO 80

65 0 DF3DF2=( F2 + 0, 4) *( F3 + 0, 2) *F3/ ( ( F 3+0 , 4

) * ( F 2 + 0 , 2) *F2)

655 DER=0,71428*(l,O-DF3DF2)+O.85 714*(DF3DF2/( F3+0. 2)-l , 0/ ( F2+0. 2)

)

660 F2=F2+ERR/ DER

66 5 Gtl 2=1.0/ F2

6 70 7 0 COriTlNMU::

6 75 PRI^rr:"VGl DID HOT r.OIIVERGE #" , X, FXODI

6 80 80 IF(GII2. LE, 0. 0) '^SETURN

f> 8 5 V 0 = S O P. T ( G r' 2 ) 6"() HC I F = V()''tS0i;0 2

6<)'^ yo RETIIKlI

7 'HI EMI)

42
Program CF

Option 6. Cold Flow

Due to the length and complexity of this program, a computer flow diagram

and a list of computer symbols are included.

150-260

Read data

~~r~

280-330

Pump scaling factors

340-390

Set initial conditions

400--440

Calc HLEV

440-460

HHR = XL4+XL5

Calc DAV

^iSO

JPST.GE.2^>-YES' XPX = PULG + 14.696

(Saturation at transfer pressure)

XPX = PSTOR + 14.696

(Saturation at storage pressure)

490-560

Calc TSTOR*, DENSL*, DRE, X0D2, ADD5 , X0D5, DT

570-590

Initialize TIM, FLOW 1, LIMIT

600-690

Calc HE, HO, PUL, BIN

OOA = 4230/DAV**0. 25 (Bare) EQ.2 EQ.O QOA =2.92

(Vacuum insulation)

QOA =16.2

(Foam insulation)

43
EXPO =2.0

(Quick opening)

GE.3

"7 C A /dO- "7 n r\ /yo

Calc QAMB

EXPO =1.0

(Linear)

lE.l830-845

Calc WVNT, PVNT*, PRECVR, PRECVRG

EXPO =0.5

(Equal percentage)

890

DO 50 NSTEP = 1, LIMIT

930-1040

Interpolate RPM or ULP to value at TIM

I

1050-

Calc HO, PIF,

1110

FOF, FRPM, FA

. DO 243 K = 1, 20

1130-1220

Calc AO*, BO*, CO*, RAD, FLOW, FLOMAX, HO

Iterate for FLOW < FLOMAX

YES-

(Final value of HO is such tha

FLOW does not exceed vaporize

capacity)

44
1300-1530

Calc FLOS, HPMP, FL86, FLOAV, RATIO, EFF, EPMP, HFRIC,

PAX, TIS*, EIS*, EFRIC, EDIS, EQ, EOUT

(Enthalpy gain)

13^0-1720

Calc POUT, POUTG, TOUT*, TVNT*, DVAP, WVFLO, PRECVR*,

TOS*, EOS*, FLOR*, FLRA, PEX

("Flow race corrected for two phase pressure drop)

1730-1820

Calc TRECVR*, DELV, FLODIS, PSUB, VSTOR, WL, HLEV, PPEX

(Variables to be stored in arrays for plotting and starting values for a new time interval)

45
1

1

Stored Array

YPLOT VS. TIM.

i

1920

FLOW.LE.FSAVE

(Establishes FSAVE as maximum flow)

YES

NO

I FSAVE = FLOW

TSAVE = TOUT

50

FLOW 1 = FLOW

continue

CALL CF2FILE

(Plotting routine)

^Calculation by subroutine in CFSUB or HPROP

46
CF - Computer Listing Symbols

AO

2 Coefficient of FLOW terms

AQ

2

Heat transfer surface area, ft

BO Coefficient of FLOW"*" terms

CO

<- ^ . ^ 0 Coefficient of FLOW terms

COEF

2 Coefficient of FLOW frictional terms only

DELV Incremental flow out of storage in DT, gal

DENSL

3 Density of LH2, lb/ft

DT Time increment, sec D1-D7 Inside diameters, in

EDIS Dissipated energy, pump, and friction, Btu/lb

EFF Pump efficiency

EFRIC Energy dissipated in pipe friction only, Btu/lb

EIN Inlet enthalpy, Btu/lb

EOS Saturation enthalpy at outlet condition, Btu/lb

EOUT Outlet enthalpy, Btu/lb

EPMP Energy dissipated due to pump inefficiency, Btu/lb

ununaipy rise uue to amDienc neauing, ijcu/XD

ERR Error in flow iteration

EXPO Exponent in equation for FA

r i\ LiOrrecLion racuor ror non linear vaive opening cnaractenstic

FLDIS(I) Array for FLODIS

FLO (J) Array for FLO

FLOAV Flow averaged over the time increment, gal/min

FLODIS Accumulated flow in receiving tank after subtracting quantity

evaporated, gal

FLOW Flow rate, gal/min

FLOWl Flow rate, at the beginning of the time increment, gal/min

FLOR Ratio of two phase to single phase flow rates

FLRA Average of FLOR

FL86 Factor in equation for pump efficiency

47
rUr Fractional closing if discharge valve

FOPN CI; Array for FSET

T7T)DT?TT rrKhV Temporary storage symbol

r KrM RPM dependent terms in equation for pump head

FSET Valve setting at time I HE Exit head corresponding to absolute receiver pressure, ft

TJT-\T.Tr\rn HDWUi Head developed from momentum change, ft

rlnK Vertical rise at receiver end, ft

HFRIC Friction head, ft

HLEV Supply liquid level, ft

nU Heaa corresponding to rKriLVK-rULij, rt

nULU Ola value or HU, rt

HTRY Trial value of HLEV at time I nUK Relative humidity, percent

TITTC Specific humidity, grains/lb

Number of the time step

VIT7AT Xr

IN VALi V Indicates type of valve (input data)

rJJ Vapor pressure corresponding to dry bulk temperature

r noL/Li Pump head scaling factor

rUU i Pressure upstream from discharge valve, psia

rUU iLr Gauge pressure equivalent of POUT, psig

PPT?V Pump discharge pressure, psig

FRhCVR Receiver pressure, psig

r DDL. Li Pump speed scaling factor

rbiOR Storage pressure of the supply liquid, psig

PSUB Pressure in excess of the vapor pressure at the discharge, psig

PULG Supply ullage pressure, psig

PVSCL Pump volume flow scaling factor

QOA 2 Convection heat flux per unit area, Btu/hr*ft

QRAD 2 Radiation heat flux per unit area, Btu/hr*ft

RADI Radicand (temporary storage)

48
3.

RPM Pump RPM

RPM(I) Array for RPM

RSPH Spherical tank radius, ft

TA Atmospheric temperature, deg F

TBUB Bubble cap temperature, deg R

TFRA Time for computing fractional valve opening, sec TIM Actual time, sec TIME (I) Time of I ' th change in conditions, sec TME(J) Array for TIM

TOS Saturation temperature at outlet pressure, deg R

TOUT Temperature upstream from discharge valve, deg F

TPRINT Temporary storage for TIME (I)

TR Absolute temperature corresponding to TA, deg R

TSTOR Saturation temperature corresponding to PSTOR, deg R

TVENT Vent gas temperature, deg R

VSTOR Storage volume corresponding to HLEV, gal

VNT Vent flow rate under static conditions, lb/sec

VTRY Trial value in iteration for VSTOR, gal

WVFLO Vent flow rate during fill, lb/sec

XK Coefficient in pressure drop through restrictions

XL1-XL9 Pipe lengths, ft

2 X3 Coefficient of FLOW in computing pressure drop at the discharge

valve

XPX Vapor pressure at the inlet, psia

XSOL Ratio of length of pipe containing single phase liquid to total

length

49
Program CF Page 1 Option 6, Cold Flow

in$USE CFSUB ;HPROP;PLnT ;CF2FILF:

2 0 COMMON FLOV/l , X0D2, X0D5, DAV, XK, FA, DT , HL E V , RPM , HO , HHR

30 COMMON HUS,TA,WFPS,COEF,NSTEP,POUT

40 COMMON TME(105) ,YPLOT(105) ,NOPT, ITSAVE, IFSAVE.NPTS

50 COMMON DRE, PHSCL, PSSCL, PVSCL, GPM

(SO DIMENSION T IME ( 6 ) , FOPN ( 6 ) , RPM 1 ( 6 ) 150 READ: XM , XL2, XL3, XL4, XL

5

160 READ: XL6, XL7, XI,8, XL9, Dl

170 READ: D2, 03, OA, D5, D6

ISO READ: D 7 , CALR , VNT , H 1

, GPM

190 READ: PUMP, SPD, PSTOR , SVOL, NVAC

200 READ:OX

210 READ: PULG, IPST,N0PT,TIME(2) ,TIME(3)

220 READ: (TIME(I) , 1-4, 6)

230 READ: ( FOPN( I) , I-l , 5)

240 REAn:F0PN(6)

250 READ: (RPMl (I) , I-l , 5)

260 READ: RPM1(6) ,NVALV

265 XE0F-XL8

2 70 222 CONTINUE

280 PHSCL-PUMP/400.

290 PSSCL-SPD/ 1 700,

300 PVSCL-GPM/ 1 0000,

310 IF(PUnP,EO.O,) PHSCL-1,

320 IF (SPD.EO,0,) PSSCL-1,

330 IF(GPM, EO, 0, ) PVSCL-1.

340 TIME(l)-0.

350 UI'^n=10,

360 FSAVE-0,

370 PRECVR-0,

380 HADD=0,

390 GAL-SVOL

400 CAP-900000,

410 IF(GAL.GE,CAP) GAL-0.99*CAP

420 RSPH-0, 31 794*CAP**0, 333

430 VUL-CAP-GAL

440 HLEV«0, 4 7 74 65*VUL/ (RSPH*RSPH)

4 50 H.HR = XT,4 + XL5

460 DAV=(XM*D1+XL2*D2+XL3*D3) /( 1 2.*(XI,1+XL2+XL3) ) ixln XPX=PST0R + 1 4, 696

4 80 IF( IPST.GE, 2)XPX=PnLG+l 4. 6 96

490 TSTOR=VATEMP(XPX)

500 DENSL=DEN(TSTOR)

510 nRE=(ni+D2+D3)/3.

520 ADD2=0.0

5 30 X0|-)2 = XL1/ ( ni*ni )+XI,2 / (n2*n2)+XT,3 / (D3*r)3)+ADD2

^40 AnD5=XE0F/ 03**5

5 50 X0n5=XM /ni *A5+XL2/ D2**5+XL3/ n3**5+ADD5

5 60 Of =TTi1E( 6 ) / 1 00, 0

5 7 0 TI1! = 0.0

5«0 FLOV71=0,1

590 LIMIT=100

600 ilK=(PRECVR+I4, 7)*144.0/nENSL

610 FLOniS=0.0

r,9i) V10= (PRRC VR-PULG) *1 44 . 0/ DENS L

6 30 PUL = PHI,G + 1 4.7 '\

640 IISTEP=1

650 X1'X=PST0R + 1 4. 696

6^-^0 T F ( I PST . r,K . ? ) XPX=POLn+l A . f,<)f, fS?" 1 STOP. = VAT'';!IP( Xl'X)

50
Program CF Page 2 680 VST()R»GAL

690 EIM=ENTH(TSTOR, PUL, IIII)

700 IF(NVAC.EO,0) OOA-2.92

710 IF(NVAC.EO.l) QOA'-16,2

720 IF(NVAC, EO, 2) OOA-4230. / DAV**0, 25

730 TR-460.+TA

740 HADD-O.O

750 AO-O. 2618*(D1*XLI+D2*XL2+D3*XL3)+HADD

760 nAItB=.0OA* AO

770 GO TO 12

780 10 OAlIR-0,0

790 12 CONTINUE

800 IF(NVALV.LE. 1) EXPO-0.5

810 IF(HVALV, EO. 2) EXPO-1,0

820 IF(NVALV.GE.3)EXPO-2.0

830 V/VNT-VNT

84 0 PRECVR-PVENT( WVNT, XL4, XL5, XL6, XL7, XL9, D4, D5, D6, D7,TBUR)

845 PRCVRG=PRECVR-1 4. 696

890 DO 50 NSTEP-1 , LIMIT

900 FLOW-FLOV/l

910 TIM-TIM+DT

930 DO 20 1-2,6

940 IT-I

950 IF(TIHE(I) .GT.TIM) GO TO 22

960 20 COHTINHE

9 70 GO TO 24

980 22 nENOM=TIME(IT)-TIHE(IT-l

)

9 90 IF( nCNOM. EO. 0. 0) OENOM=0. 001

100 0 TFRA=(TIM-TIME(IT-1 ) ) / ( T IME ( IT ) -T IHE ( IT-1 )

)

1010 FSET-F0Pn( IT-1 )+(F0PH( IT) -FOPN( IT-1 )) *TFRA

1 02 0 RPH = RPM1 (IT-1 ) + ('RPMl (IT) -RPIll (IT-1 )) *TFRA

1030 IJLP-PULG

1040 IF(GPM. EO, 0, ) ULP«=RPM

1 0 30 !'0 = (PRGVRG-IILP) *1 44 . / PENS L

1 052 PIF-1 , 41 E-07*FLOIJ**2

1 055 IF(IILP.GT.30.)HO = HO + PIF*144./DENSL

1060 24 FOF-l.O-FSET

1070 RPM3=RPn*PSSCL

10«0 FRPII=.-3, 782475 + 0, 01 62881 335*RPnS-)-0. 261 0459 E-3*RPMR**2

10 90 IF(FOF,LE.0.0)FOF-0, 0000001

1100 IFf FOF, GE, 1 . 0) FOF-0, 999

1110 F A=l . 0/ ( 1 , 0-FOF**EXPO) **2-l ,

0

1120 no 2 43 K-1,2 0 1130 A0=AF(Dl,n5)

11 40 RO = a F( ilT )

I I SO TF( HSTEP. EO. 1 ) B0 = 0,

0

1 160 cn = cF( Kprts)

1170 HAni=RO**2-4 . 0«AO*CO

11 PO I F( RAni . GT . 0. 0) GO TO 2 5 u 'H) riAn 1=0.0

1 200 2 5 FLOi,;= ( RO-SORT ( RADl ) ) / ( 2 . 0* AO)

1210 FI,oiiAX=35746.*Pni,**0. 81 7059

1220 IF(GPM. EO.O.) FL0HAX-99999.

1 9 30 IF(K. En, 1 , Aim. FLOU.LT, FLOflAX) GO TO 244

1 240 r)H = -10.

1 2 SO I F ( f . GT . 1 ) Tfl= (HOLO-HO) * ( FLOtT AX-F L0\; ) / ( FLOLP-FLOU)

12fSo lW) = ;io + T)ll

1 2 70 iH)M) = :io i?."o F;,oT,n = rLou

12^10 2 4 3 cotiTirnn-:

1 3 00 2 A4 FL0S = FL0U/ PVSCl.

1 3 1 0 2 7 'I Pr!P=FRPn-0. 482 2 51 1 E-6*FL0S* AT, S ( FLOS ) 132 0 I F f n p;l. F,(). 0. ) MP;!P = 0 .

51
Program CF Page 3 1330 IF ( FLOW.GT.O. 0) GO TO 30

1340 EFF-0.0

13 50 EPMP«0,0

1360 FLOW=0.I

1 3 70 GO TO 3-2 1380 30 FL86-2003, 879+16, 1913*HPMP-0.0106583*HPMP**2

1390& +0. A40906E-5*HPHP**3

1400 FL0AV»'(FLOU + FL0Wl)/2.

1410 RATIO-FLOVJ/ FL86

1 420 EFF-0. 86-0. 854997 + 2. 31 2442*RATIO-2 . 36 3 03 6* RAT 10** 2+0 . 906 5 75

1

1430& RATI0**3

1440 EPMP=1.2851E-3*HPMP*(1.0/EFF-1.0)

1450 32 HFRIC=C0EF* FL0W**2

1460 IF(GPH. EO. 0, ) HFRIC-0,

1470 PAI=>PUL+(HLEV+HPMP-HFRIC) *DENSL/ 1 44,

1480 TIS-VATEMP(PAI)

1490 EIS-ENTH(TIS, PAI, IVI)

1500 EFRIC-1 , 2851E-3*HFRIC

1510 EIUS-EPMP+EFRIC

1 520 E0 = 0, 1 2466*0AMB/FLOV;/DENSL

1 530 EOUT«E IM+EPtlP+EFRIC+EO

1 540 XSOL=(EIS-EIN) / (EIS-EIN+EOIJT-EOS)

1550 IF(XSOL.LT,0.)XSOL-0,

1 560 IF(XSOL. GT. 1 . ) XSOL-1 , 1570 X3=7. 198E-3*FA/n3**4

1 580 HnUDT-O. 1 3601 95*(FLOV/-FLOW1)

1 590 POUT=(11E+X3*FLOV;**2)*DENSL/144.

,1 595 IF(lJLP,GT. 30.)POIJT-POUT+PIF

'1600 poutg = poi;t-i A. 7 1610 TOUT-TEMPCEOUT , POUT , FR)

1 620 TVMT»TEtIP(E()UT, PRECVR, FRV)

163 0 nVAP»0. 18635*PRECVR/TVNT

164 0 UVFLO-VNT+2. 2 2 8E-0 3* FLOW* ( FR V* DENS L+ ( 1

, -FR V

) * D VAP

)

1 65 0 PRECVR-PVEMT(WVFLO, XL4, XI,5, XL6, XL7, XL9, D4, D5, D6, D7, TBUB)

1660 TOS=VATEMP(POUT)

1670 EOS=EMTH(TOS, POUT, IVO)

1 6r,0 FI,R A = 0 . 3* ( FLOR ( FR , TOUT , POI'T ) * ( 1 . -XS0L)+1 .+XROL)

1600 IK( FLRA. LT . 0. 1 ) FLRA=0.

1

•1 700 I K( FI.RA. GT . 1 , 0) FLRA=1 . 0 1710 FLO\; = FL0V;* FLRA

172 0 PEX=PRECVR+1 4,

7

1730 TRECVR=VATEMP(PRECVR)

1 740 nELV=riT*FT,OAV

1750 FL0niS=FL0ni3+DGLV

17^0 1>SIIB = F0UT-VAP0(T0UT)

177'^ VST')R = VST!)R-UEI,^'

17?^(^ TF( VSTOR.LE. 0. 0) GO TO 9«3

I 7"0 VU1, = CAP-VST0R

1 "no l'LEV=2.*RSPH-0 . 4 7 74 65*VUL / (RSPII*RSPn)

1 » 1 0 PPi' X=PULG+(H!.RV+1 0. - 2 . 2 1 2 7 E - 8 * FLOW* * 2 +'n'M P ) *DRMSL / 1 44,

1 21) 40 TME(nSTr:P)=TIil

1830 IF(iinpT. LE. 1 ) YPLOT (tISTKP) =FI.OVJ lP/,0 I F ( Mt) PT . EO. 2 ) YPLOTCiISTEP)=FI.nnis

1830 IF(i!OPT. EO. 3) Y PLOT ( N S T E P ) -T R EG VR

IRf^n IF( flOPT. EO. 4) YPLOT(i^STEP)=TBUH

1870 IFdJOPT. EO. 5) YPLnT(t)STFP)=FR

1 880 I F( rIOPT . GE . 6 ) Y P LOT ( !^ S T r, P ) = V S TO R ]"'I3 n P(^ = UO* OEMS L/ 1 44 , 0 lj2n IF( FLOIJ.LR. FSAVE) GO TO 45

1^30 FSAVF = FLOV.'

1 94" TSA"'' = TOUT

1 Q S f) /, 5 K LOW 1 =FL0i; '

- I'KiO ?ip'rs = nsTFP ,'

52
Program CF Page 4 1970 50 COHTINUE

1980 983 TME(I]PTS + 1 )-TIME(6)

1990 IFSAVE=FSAVE

2000 ITSAVE-TSAVE

2010 TME(NPTS+2)-0.

0

2020 CALL CF2FILE

2030 999 STOP

2040 END

Subroutine CF2FILE

Graph Headings and Labels for CF

10 SUBROUTIi-IE CF2FILE

2n COMMON FLOl/l,XOD2,XOD5,CAV,XK,FA,DT,HLEV,RPM,HO,HHR

30 COMMON HUS.TA.WFPS.COEF, MSTEP, POUT

40 COMMON TME(105) ,YPLOT(105) ,NOPT,ITSAVE, IFSAVE.NPTS

50 ASCII A(42) ,B(14) ,C(7)

60 ENCODE (B,10)

70 10 F0RMAT(56X)

80 GO TO (1 , 2, 3, 4, 5, 6) ,N0PT

90 1 ENCODE (C, 11)

100 11 FORMAT ( 7X, " FLOV; RATE GPM",8X)

110 ENCODE (R, 17) IFSAVE , ITSAVE

120 17 F0RMAT(4X, "DISCHARGE TEMP AT A FLOVJ OF", 16," GPM WAS", 14," R" , 5X).

130 GO TO 7 140 2 ENCODE (C, 22)

150 22 FORMAT("TOTAL LTOUID DISCHARGED GAL ")

160 GO TO 7 170 3 ENCODE (C,33)

180 33 FORMAT("RECEIVER LIOMID TEMP DEG R ")

100 GO TO 7 200 4 ENCODE (C,44)

210 44 FORMAT ("BUBBLE CAP TEMPERATURE DEG R"

)

2 20 GO TO 7

2 30 5 ENCODE (C,55)

2'iO 55 FORMAT(" EINAL VAPOR MASS FRACTION ")

2 50 GO TO 7

2 6f^ 6 r, NCOnc (C,*^^)

2 70 66 FOH!(AT("REMAINING LIOUID VOLUME GAL ")

2,SO 7 rJCODE (A, 73) B

2')() 73 F0RHAT(8X, " STEADY OPERATION AND TRANSIENT RES PONS E" , 20X , 30')f< "TO CHANGES IN OPERATIi^JG C 0 N D IT 10 U

S

" , 1 1 X , 1 4A4

)

31') IK('!PTS,LT. 100) ENCODE (A, 75) B 32') 75 F0R!1AT(8X, "STEADY OPERATION AND TRANSIENT R ES PO NS E" , 1 7 X , 3'^Of. "Lionin SUPPLY DEPLETED BEFORE FINAL T IM E" , 8X , 1 4A4 ) 340 liMCOUE (B,77)

350 77 FOKMAT(20X, "TIME IN M I?-I UT E S

"

, 2 1 X

)

360 YPL0T(NPTS + 1 )=(). 0 37-1 YPLOT ( NPTS-f 2 ) =YPLOT ( 1 ) 3:;n CALL GKAPI! ( A , K , C , PT S , TM E , Y PLOT ) 3'>n r;-, rmiN

4 0 0

53
Program CFSUB

Pressure Drop Functions for CF

10 FUMCTIOM AF(D1,D5)

2n COMMON FLO\;i , X0D2, X0D5, DAV, XK, FA, DT , HLE V , RPM , HO , HHR , 3 0&HUS , TA, WFPS, COEF, NSTEP, POUT

35 COMMON TME(105) ,YPL0T(105) ,NOPT, ITSAVE, IFSAVE.NPTS

40 COMMON DRE, PHSCL, PSSCL, PVSCL, GPM

50 FPMP=PHSCL/PVSCL**2

(SO IF( GPM. EQ. 0. ) FPMP-O,

70 IF (HSTEP.GT. 1)G0 TO 20

80 PDI*2. 21 70401E-08*FPMP

90 PC4>-4. 82251 1 54E-07*FPMP

100 PDC-3, 109385599E-2

110 RC-2,5911E-3

1 20 TC = 7. 198E-3

130 X10-XOD5*PDC

140 20 RR-FL0W1*1 5359. /DRE

150 IF( RE. LT. 3. OE+03) RE-3.0E+3

160 F-0. 0055*( 1 .0+(2. 7 7+1 .E+06/HE)**0. 3333 3)

170 X1-F*X10

180 X3"TC*FA/D5**4

190 C0EF=PDI+X1+X3

200 AF--PC4-C0EF

210 RETURN

220 END

230 FUNCTION BF(X)

240 cornioN flow i , xod2, xod5 , dav, xk, fa, dt , hlev, rpm, ho, HHR

2 5 0f»HUS,TA,WFPS,COEF, NSTEP, POUT

260 CM-2 . 1 1 47G-04*XOn2

270 BF-CM/DT

280 RETURN

2 9 0 END

300 FUNCTION CF(X)

3 1 0 COHUON FLOW 1 , X0D2 , X0D5 , DAV, XK, FA, DT , HLE V, RPM , HO , HHR

320&HUS , TA, WFPS , COEF, NSTEP, POUT

330 CH=2 . 1 1 4 7E-04*XOD2

340 PC3=2 . 61 0459E-4

350 PC2»1 , 62881 3355E-2

3 60 PC 1-3. 7 82 4 75

3 70 RPMSC-RPM*PSS.CL

3^0 X1=?C2*RPMSC

39n X2=PC3*RPMSC**2

4 0 0 X3 = CM* FLOW 1 / DT

410 I F( FLOW 1 . KO. 1 00 . ) X3 = 0 ,

0

A20 FP;iP=(-PCl+Xl+X2)*PRSCALE

4 311 CF = in,R V-PC l+Xl+X2-fIO-HHR+X3

4 4') !l!^TIIH;! 4 50 END

54
Function HPROP Page 1 Hydrogen Properties, Vent and Tvo Phase Flow Functions for CF

10 FUNCTION VAPO(TR)

20 DIMEflSIOH 3(A)

30 DATA 3/2. 0062, 50. 09708, 1 . 0044 ,. 01 748A95

/

40 T=TR/1.8

5 0 VAL0G=3 { 1 ) -B ( 2 ) / ( T+3 ( 3 ) ) -^3 ( 4 ) *

T

60 VAT!!=10.**yALOG

70 VAPO =VATM*14,696

80 RETURN

90 END

100 FUHCTION XLR(?0)

110 IF(PO.G£. 187. 5) XLH=0.01

120 IF(P0.LT. 187. 5)XLH.= 2n. ^^5 7 7* (I 87 . 5-PO) **n . 4 2 7^^1 2 130 RETURN

140 EMD

150 FIIMCTIOfT npnTVP(T)

160 TK=T/l.f

170 PVA=VAP0 (T) / 1 4 . f;96 180 ELOf;=0. 434294

190 DERIV=PVA/ ELnf;*(50, 09708/(TK-^l , O044)**2-^0. 01 748495) ' 200 npnTV?=DERIV*14. 696/1 .

210 RETU^llI

220 EMI)

230 FlTHCTIOfT EMTH(T , PS I , IF)"^

240 DI"EriSIOIl A(4)

250 TK=T/1.8

260 P=PSI/14.696

270 DATA A/-0, 05720323, 2. 794294, -61 , 70376 , -70. 95291/

280 C=32.72-TK

29 0 RSAT = A( 1 ) *C**3-!-A( 2 ) *C**2+A( 3 ) *C-^A( 4 ) 300 PSAT=YAP0(T)/14.696

310 3T1=0. 002 321 08*TK*TK-0. 089 7 88 2*TK+0. 831432

32 0 BT2=-0. 074 8928*TK*TK+2. 764046 *IK- 21. « 8 605

330

340 p::=p-psat

350 h0fp = bt1*?x*px-^bt2*px

360 EN"rM = 0. 21 3377*(!iSAT+HnF?)

370 IF=1

3 H o I F ( P . r.T . P S AT ) ^. E T TT R :7 39" IF=0

4 00 E:TT ! = ••'? AT* 0. 221<?6S

41 0 RE'i' 420 c^in

430 Fl'tlCTIrt'l VATE"IP(PORS)

/ AO PLOn=0. 4342944P*ALOG( POBS / 14,606)

450 Cl=2.01fJ18

Uf,n r?=3. 9661 7 470 C3=7. 43630

4 80 f;4 = 0, c)34 96 9 9

/ < i< Tp:=( PLOG-C IJ-SORT { P LOG* PLH G-C 2*PLn r.J-C 3 ) ) / C4

^'ATE!1P=TK*1 ,

?^

I 531- k t .ir. Ll'in TE?IP(H, P, FK)

540 5 T l=VATE!f P(P)

SSn !!l=E-."i !:(Tl , P, II-

)

SiSn XI. = '"T.!' ( P)

3 7" F!"=( !-!Il) /XL

^ ' '»E?JP=T1

:f(fr,gt.i.o) fu=i.o

IF ( F5t. GE. 0. PI '^T"":'

;R=0.0

( ; I n im 40 h=l , 2(1 '.3'1 12 T2=Tl-0.oni

55
Function HPROP Page 2

6 AO lA H 1=ENTH(T 1, P, IF)

650 16 H2=ENTH(T2, P, IX)

652 IR A=(T1-T2) / (H1-H2)

655 ERR=(H1-H)/H

660 20 IF(ARS(ERR) .LT. 0.001) GO TO 42

6R0 22 T1=T1-(H1-H)*A

690 AO CONTINUE

700 PRINT 100

710 A 2 TEMP = T1

720 RETURN

730 1 00 FORtlATC SUBROUTINE TEMP DID NOT CONVERCE ")

7 AO END

750 FUNCTION DEN(TSTOR)

760 nO=5. 3A3989

770 ni=-7. 70289E-03 s 780 D2=-5. 138191E-OA

790 DEN=D0+ni*TSTOR+D2*TSTOR*TSTOR

80 0 RETURN

810 END

82 0 FUNCTION P VE NT ( W VNT , XL A , XL 5 , XL 6 , XI, 7 , XL 9 , D A , D 5 , D6 , D 7 , TB UR ) 830 DIMENSION TA V ( A )

, FD P ( A

)

B35 REAL KE • 8A0 KE=-1 . A75E-05

850 TU=36.

860 no 1 1 0 J=l , A 870 00 TO ( 1 02, 103, lOA, 105) , J 880 102 XL=XLA

890 n=nA

900 GO TO 106

910 103 XL=XL5

920 n=n5

9 30 00 TO 106

9A0 lOA XL=XL6

9 50 n=D6

96 0 00 TO 106

970 105 XL=XL7

980 D=n7

99 0 '/i: = -A , A68E-0 5 1000 106 TR=5AO.-(5AO,-TU)*EXP(KK*D*XL/WVNT)

1 004 r,>;po = EXP(KE*nAXL/WVirD

lOlf) TA"( J) = (TU+TR) /2,

1 02 0 TU = T!l 103 0 TK=TR/ 1 .

8

1 OAO VIS = -n . 0960808E-0 7*TK**A+0. 0792 29 3E-0A*TK** 3-0. 2562 Al 5E-02*TK*Tf^

10 50f. +0.61A789AATK,-0,A933261

1060 VIS02 . Al 91 E-OA*VT S

1 0 7 0 FDP ( J ) = 0 . 901 99*XL*VISC**0 . 2*1/ VNT** 1 . 8 / D** A , 8 lOKO 110 ooriTii-iur,

10 9 0 T H [111 = T R : _ :

1 1 nil P Dfi = P VK MT

1 1 111 l'A\? = i A. f^qf,

1 1 9 ;> n n = 1 4 . 6 9 6 1130 nf) 1 76 !'.= 1 , A

I 1 /,() I = S-'/ 1150 no 120 J=l , 20

11^0 !>r,AS = n. is635*PAV/TAV( I)

1170 np=cnp(i) /iir.AS

1 1 'r'o p:i!';\' = pnri+o . 5*np

I I 'HI pvr:'JT = i^nn + np

l?o(^ It' ( A« s ( priEU-PA V) / pni",v; . LT . 0 . 000 1 ) oo to 126

1 1 0 I'A v=ptii':',' 12 20 120 CONi I'HO: 12 30 PR I'lT : " i^vr riT KAILF. n TO COMVEKOK"

56
Function HPROP Page 3 1240 PVENT=14.696

12 50 no TO 127

1 260 1 26 COHTI^^UE

12 70 127 KETURM

1280 END

1300 FUNCTION FLOR ( FR , TOUT , POUT

)

1310 IF( FR.GT. 0, 00001 ) YF=SORT( ABS ( ( 1

. -FR) /FR)

)

1315 IF (FR.LE.0.00001)YF=0,0

1320 BTA=1 . / ( 1 ,+0. 37988*YF)

1330 TH-0.875988+7,94 4 0*EXP(-16.32928*(BTA-0.5)**2)

1340 IF(TH.LE.1,0)TH-1.0

13 50 DR=DEN(TOUT)*TOUT/0. 186 35/ POUT

1360 SRTH=SORT( ARS(TH)

)

13 70 SRn=S0RT( ABS (0. 59941*DR*FR** 1 . 8+( 1

. -FR) **1 . 8)

)

1380 FL0R=1 . 0/ SRTH/ SRD

1390 RETURN

14 0 0 END

Subroutine PLOT Page 1 Plotting Subroutine for all Programs

10 SUBROUTINE GRAPH ( A, B , C , N , X, Y

)

20 DIIIENSION A(42) , R( 1 4) , C( 7) , X( 1 03) , Y( 1 03) , S ( 1 2)

30 ASCII A,B,C,S

40 IF (N.GT.O) GO TO 7 50 PRi:>}T 3

6 0 1 RETURN

70 3 FORMAT(lX,"&f.")

80 7 PRI;JT in,A,B,C

90 10 FOR:fAT(lX,"&" , 14A4)

ion L=U+2

lin xH=xfl)

120 XL=X(1)

130 YH=Y(1)

140 YL=Y(1)

1 50 0(1 2 0 1 = 2 , L 160 IF(X( I) .GT. XH) XH = X(I)

170 IFfX(I) .LT.XL) XL=X(I)

IPO I1<(Y(I) .GT.YH) YH=Y(I)

190 IF(Y(I) .LT. YD YL = Y(I)

2f)0 2 0 CyNTINlIK

210 CALf, SCALR (XI,,XH,S)

2 20 P III .IT 11,S

?30 CALL SCAI,r (YL,Y"l,S)

2 40 11 l< ORllATn X, "f," , 2A4, 4X, 2A4, 3X, 2A4, 4X, 2A4, 3X, 2A4, 4X, 2A4)

2 so no 22 1 = 1,12,2

2r-,0 2 2 PiUiT 1 0, S ( I ) , S ( I + l ) 2 71) 0X= ( XH-XL) / 800 . 2Pn nY=(YH-YL) /6on.

2 9!) 2 7 XORilATC IX, "f," , 2T4)

3 00 no 33 1=1,

n

310 IX=1 30. 5+(X(I)-XL) /nx

32 0 iY=r>6.5+(Y(I)-YL)/DY

"^3 0 3 3 V'.IJ'VC 2 7,I)(,IY

3 4 0 ? II I n T 3 3 SO 4^. RSA;):IX

U-.0 IV (I '.'-1 ) A A , 1 , A 7 37f) A7 '•V = XL-^(IX-I 30) *nx

38 0 no I = ?,il

57

<
Subroutine PLOT Page 2 390 IF{XV.LE.X(I)) GO TO 66

400 55 COHTINUE

410 i-ri 420 66 YV=(XV-X(I-1))/(X(I)-X(I-1))*(Y(1)-Y(I-1))+Y(I-1)

4 30 PRINT 7 7,XV,YV

440 77 F0RMAT(1X,"&X «",1PE9.2,", Y =-",E9.2)

4 50 nn TO 44

4 60 END

470 SUBROUTINE SCALE (XL.XH.S)

480 DIMENSION S(12),T(2)

490 ASCII S,T

500 I=ALOG(XH-XL) /2. 3025851-

510 I-I-l

520 r)=10.0*AI

530 IF(XL)7,8,8

540 7 IL=XL/D-.999

5 50 GO TO 9

' 560 8 IL=XL/D

5 70 9 IF(XH) 11 , 1 1 , 1 2

5 80 11 IH=XH/D

5 90 GO TO 13

600 12 IH=XH/n+.999

610 13 J=(IH-IL+4) /5

620 XL=IL*n

630 XH = XL

640 IF ( I) 1 4, 1 7, 18

6 50 14 IF(I+2) 16,19,15

660 15 1=4

6 70 GO TO 2 0

6 8 0 16 1=1

6 9 0 GO TO 2 0

7 0 0 17 1=2

710 GO TO 2 0 720 18 IF(I.GT.6) GO TO 16

7 30 1=3

740 GO TO 20

7 50 19 1=5

' 760 20 no 30 K=l , 1 2 , 2 770 GO TO (21 , 22, 23, 24, 25) ,

I

7 so 2 1 Eficonr: (t,31) xh

7<M) GO TO 2 7 300 2 2 ENCOnE (T,'32) XII 81(1 (;o TO 2 7

^^ 2 0 2 3 Ii'=XH

8 30 !• ^'CO0E , 3 3 ) I E yiiO GO TO 2 7 850 2 4 EnCOnF, (T,34) XH

8(S(! GO TO 2 7 S 7 0 2 5 EjICOPE (T,35) Xil 880 07 S(K)=T(l)

o.'in r, (r + l)=T(2)

9f;(i 30 ^c:i = vH4.jAr)

910 x:i = X!,-^5* J->0 • •'20 iI;-:T!IK:J •nn 31 KOlltl AT ( 1 Pi' 8 . 1

)

94" 32 i'0H.r[AT(F8. 1 ) ')3() 3 3 F()K11AT(I8)

'J60 34 FilHMAT(F8.2)

"7" 3 5 '-'ITiIAT ( F!^ . 3 ) '18 0 El]n

58
Program DATFILE

Prints Date and Time on Input and Output Figures

10 lUMENSIOlJ DATP, (2)

20 CALL r)ATE#TIME(DATE,TIME)

30 PRINT 10, DATE, TIME

40 10 FORMAT(X, lHf< , 2A4, F8. 3)

50 END

59
»Bi MA (REV. 7-73)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO.

NBSIR 75-820

2. Gov't Accession

No.

3. Recipient's Accession No.

4. TITLE AND SUBTITLE

STUDY OF CRYOGENIC PROPELLANT SYSTEMS FOR LOADING THE

SPACE SHUTTLE - PART II, HYDROGEN SYSTEMS

5. Publication Date October 1975

6. Performing Organization Code

7. AUTHOR(S)

w. G. Steward

8. Performing Organ. Report No. NBSIR 75-820

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 2750458

11. Contract/Grant No. CC-37171A

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

National Aeronautics and Space Administration

John F. Kennedy Space Center

Kennedy Space Center, Florida 32899

13. Type of Report & Period Covered

r xnai

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual summary of most si^ificant information. If document includes a significant

bibliography or literature survey, mention it here.)

This report covers computer simulation studies of liquid hydrogen

fill and vent systems for the space shuttle. The computer programs

calculate maximum and minimum permissible flow rates during cooldown

as limited by thermal stress considerations, fill line cooldown time,

pressure drop, flow rates, vapor content, vent line pressure drop and

vent line discharge temperature. The input data for these programs

are selected through graphic displays which schematically depict the

part of the system being analyzed. The computed output is also displayed in the form of printed messages and graphs. Digital readouts

of graph coordinates may also be obtained.

Procedures are given for operation of the graphic display unit

and the associated minicomputer and timesharing computer.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons)

Computer modeling; cooldown; cryogenic flow; stresses; two phase flow.

18. AVAILABILITY [X] Unlimited 19. SECURITY CLASS

(THIS REPORT)

21. NO. OF PAGES

1 For Official Distribution. Do Not Release to NTIS

UNCL ASSIFIED 64

1

' Order From Sup. of Doc, U.S. Government Printing

Washington, D.C. 20402. SD Cat. No. C13

Office 20. SECURITY CLASS

(THIS PAGE)

22. Price

l)( ! Order From National Technical Information Service

Springfield, Virginia 22151

(NTIS)

UNCLASSIFIED

$4.25

USCOMM-DC 29042-P74