/

•' FR-18046-3

12 DECEMBER 1984

L

;_. DESIGN AND ANALYSIS REPORT

FOR THE RL10-11B BREADBOARD

'i LOW THRUST ENGINE

1

FINAL REPORT

1

__ CONTRACT NAS3-24238

l

!

!: Prepared for "

_: National Aeronautics and Space Administration "

i Lewis Research Center , t

i. 21000 Brookpark Road _:

,: Cleveland, Ohio 44135

k

,

t

Prepared by

United Technologies Corporation

Pratt & Whitney

Government Products Division

P.O. Box 2691, West Palm Beach, Florida 33402

UNITED

TECHNOLOGIES

PRATT&WHITNEY

Prltlled in lhQ UntllKI SIIIIII of A '
Pratt & Whitney

FR-18046-3

FOREWORD

Thisreportpresentthe s designandanalysiofstheRLI0-11Bbreadboard!owthrustengine

which was initiatebyd ContractNAS3-22902and issubmittedin compliancewith the

requirements ofContracNAS t 3-24238.

ThisprcjecwtasinitiatiendOctober1982andthefinarleportwasdelivereindDecember

1984.The effortwasheadedbyJosephS.Henderson,ProjecEngin t eer.

The followingindividuahlasveprovidesdignificacontribution nt iths epreparationofthis

report.

James R. Brown

: Robert R.Foust

Donald E. Galler

Paul G. Kanic

Thomas D. Km;_¢

Charles D. Limerick

Richard J. Peckham

Thomas Swartwout

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Pratt & Whitney

FR- 18046-3

SUMMARY

The breadboard low thrust RL10-IIB engine is shown in Figures I through 4. The steadystate cycle analysis data and schematics shown in Figures 5 and 6. The breadboard engine

utilizes a three stage oxygen heat exchanger (OHE) and four open-loop, hydraulically-actuated

breadboard control valves, which were adapted from earlier throttling engine programs. The

steady state and transient RL10-IIE engine cycle analyses shown in Section III were based on

anticipated flight propellant inlet pressures of 20 psia for both fuel and oxidizer in order to

provide data for the "flight representative" valves and OHE designs. The first engine test series

using the breadboard design will be performed at fuel and oxi,iizer inlet pressures of 25 psia and

33 psis respectively, because the Pratt & Whitney (P&W) E-6 test stand cannot currently

provide the flight-representative inlet conditions. Sections IV and V provide the design/analyses

of the OHE and the breadboard valves, respe_ively.

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Pratt & Whitney

FR-18046-3

Figure 1. Bread&_ardLow-Thrust RLIO-IIB Engine (View I)

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FE2250_2

Figure2. Breadboard Low-Thr_t RLIO-IIB Engine (View 2) v

®
FE 225030

8.4%12

9992B

Figure 3. BreadboardLow-Thrust RLIO-IIB Engine (View 3)

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FR-:B046-3 '_

' OF,POOR QUALrI'_

FE 225031

840412

99928

Figure 4. Breadboard Low-Thrust RLIO-IIB Engine (View 4)

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FR-18046-3

CONTENTS

Section Page

I INTRODUCTION .................................................................. 1

J,

II DEFINITION AND REQUIREMENTS ...................................... b

A. Description ................................................................. 4

B. Operation .................................................................. 4

III ENGINE CYCLE ANALYSIS .................................................. 7

IV HEAT EXCHANGER ANALYSIS AND DESIGN ........................ 67

V BREADBOARD CONTROLS DESIGNS .................................... 79

APPENDIX A -- Engine Steady State Cycle Calculations ............. A-1

APPENDIX B -- Definition of Engine Transient Characteristics .... B-1

'";.::.! ;XC PACE PLANK NOT Fff.MF.I_

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ILLUSTRATIONS

F_ure a'_age

1 Breadboard Low-Thrust RL10-IIB Engine (View 1) ....................... iv

2 Breadboard Low-Thrust RLi0-IIB Engine (View 2) ....................... v

3 Breadboard Low-Thnmt RL10-IIB Engine (View 3) ....................... vi

4 Breadboard Low-Thwst RL10-IIB Engine (View 4) ....................... v;;

5 RL10-IIB Breadboard Engine -- Tank Head Idle (THI) Operatin5

Mode ................................................................................... ,dii

6 RL10-IIB Breadboard Engine -- Pumped Idle (PI) Operating Mode . ix

7 RL10-IIB Engine Configuration ................................................. 3

8 RL10-IIB Engine Multimode Operation Capability ........................ 4

9 RL10-3-3A Engine F!vw Schematic -- Current Design Provides

Single Thrust Level ................................................................ 5

10 RL10-IIB Engine -- GOX Heat Exchanger and Throughflow Control

Valves are Primary Changes ..................................................... 5

11 RL10-IIB Engine Operation at Pumped Idle (Breadboard Test Series

Inlet Conditions) .................................................................... 10

12 RL10-IIB Engine Operation at Pumped Idle (Flight-Representative

Inlet Conditions_ ................................................................... 11

13 RL10-IIB E" " _,ration at Pu_ped Idle (Flight .Representative

Inlet Condi_ .te_sed Injector Area) ................................... 12

14 RL10A-3-3 Fuel Pump Operat:ng Characteristics .......................... 13

15 RL10A-3-3 Oxidizer P-ar.,p Oporating Characteristics ..................... 14

16 RL10-IIB Engine Preliminary Configuration -- Tank Head Id)_

(THI) Opetatin, Mode ............................................................ 15

17 RL10-iIB Engine Preliminary Configuration -- Pumped Idle (PI

Operating Mode ..................................................................... 16

18 RL10-IIB Engine Preliminary Configuration -- Full Thrust Le, el ... 17

19 Preliminary Analysis of RL10-IIB Engine Start to Tank Head Idle

Mode Transient (Mixture Ratio and Chamber Pressure versus Time) 19

20 PreliminalT' Analysis of RL10-IIB Engine Start to Tank Head Idle

Mode Transient (Pump Housing Temperature versus Time) ........... 20

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FR-18046-3

ILLUSTRATIONS(Continued)

Figure Pa_

21 Preliminary Analysis of RL10-IIB Engine Start to Tank He_d Idle

Mode Transient (Oxidizer and Fuel Flowrates versus Time) ........... 21

22 Preliminary Analysis of RL10-IIB Engine Start to Tank Head Idle

Mode Transient (Oxidizer Injector Inlet Temperature and Fuel

Turbine Inlet Temperature versus Time) .................................... 22

23 Preliminary Analysis of RL10-IIB Engine Tank Head Idle to

Pur-ped Idle Mode Transient (Fuel Pump Speed, Mixture Ratio, _nd

Cha__berPr_ss,_e versus Time} ................................................ 23

24 Preliminary Analysis of RL10-IIB Engine Tank Head Idle to

Pumped Idle Mode Transient (Oxidizer Flowrate, Fuel Flowmte,and

Thrust Level versus Time) ....................................................... 24

25 Preliminary Analysis of RL10-IIB Engine Tank Head Idle to

Pumped Idle Mode Transient (Oxidizer Injector h 'et, Fuel Injvctor,

and Turbine Inlet Temperature versus Time) .............................. 25

26 RLI0-11BEngineTransien--t Pumped IdleMode toFullThrust

(ChamberPressureversusTime) ............................................... 26

27 RL10-IIB Engine Transient -- Pumped Idle Mode to Full Thrust

(FuelPump Spe_dVersusTime) ............................................... 26 i

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28 RL10-IIB Engine Transient -- Pumped Idle Mode to Full Thrust

(Chamber Mixture Ratio versus Time) ...................................... 27

29 RL10-IIB Transient -- Pu,.nped Idle Mode to Full Thrust Level

(Turbine Inlet Temperat.re versus Time) ................................... 27

30 RL10-IIB T, ansient -- Turbine Bypass Valve (TBV) Parameters

(Pumped Idle Mode to Full Thrust) .......................................... 28

31 RLIC-IIB Transient -- G.seous Oxidizer Valve (GOV) Parameter

(Pumped Idle to Full Thrust) ................................................... 29

82 RL10-IIB Transient -- Thrust Control Valv_ (TCV) Parameters

IPumped Idle Mode to Full Thrust) ......................................... 30

33 RL10-IIB Engine Preliminary Updated Configuration -- Tank Head

Idle (THI) Operating Mode ...................................................... 31

34 RL10-IIB Engine Preliminary dpd_ted Configmation -- Pumped Idle

(PI) Operating Mode ............................................................ 32

35 RL10-IIB Engine Prelimi,_ary Updated Configurati_)n--

Full Thrust Level ................................................................... 33

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ILL! .,,RATIONS (Continued)

F_'ure Page

36 RL10-IIB Engine Operation (10% Thrust Level) .......................... 34

37 RL10-IIB Engine Preliminar] Configuration -- Updated

Flow Schematic ..................................................................... 36

38 RL10-IIB Engine _lternative (Gas/Gas) Cov£1_u-ation FLow

Schematic ........................................................................... 37

39 RL10A-3-3 Fuel Pump (2-Stages) .............................................. 38

40 RL10A-3-3 Oxidizer Pump ..................................................... 39

41 RL10-IIB Alternative Configuration Cycle Deck Results ................. 40

42 RL10-1IB Engine -- Alternative (Gas/Gas) Configuration Flow

Schematic -- Tank Head Idle (THI) Operating Moue ................... 41

43 RL10-IIB Engine -- Alternative (Gas/Gas) Configuration Flow

Schematic -- Pumped Idle (PI) Operating Mode .......................... 42

44 RL10-IIB Engine -- Alternative (Gas/Gas) Configuration Flow

Schematic -- (l_fll Thrust Level) .............................................. 43

45 RL10-IIB Baseline Engine -- Tank Head Idle (THI) Operating

Mode ................................................................................... 45

46 RL10-IIB Baseline Engine -- Pumped Idle (PI) Operating Mode ..... 46

47 RL10-1IB Baseline Engine -- Full Thrust Level .......................... 47

48 RL10-IIB Oxidizer Heat Exchanger Performance Data -- Pumped

Idle Mode ........................................................................... 48

49 RL10-IIB Updated Baseline Engine -- Tank Head Idle (THI)

Operating Mode ..................................................................... 49

50 RL10-IIB Updated Baseline Engine -- Pumped Idle (PI)

Operating Mode ..................................................................... 50

51 RL10-IIB Updated Baseline Engine -- Full Thrust Level .............. 51

52 RL10-IIB Engine -- Tank Head Idle to Pumped Idle Transition

(Chsmber Pressure versus Time) ............................................... 52

53 RL10-IIB Engine -- Tank Head Idle to Pumped Idle Transition

(Chamber Mixture Ratio versus Time) ....................................... 53

54 RL10-IIB Engine -- Tank Head Idle to Pumped Idle Transition

(Fuel Pump Speed versus Time) ............................................... 53

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. ;- ILLUSTRATIONS (Continued)

B-

:_* Figure Page ¥,

_ 55 RL10-IIB Engine -- Tank Head Idle to Pumped Idle Transition

(Turbine Inlet Temperature versus Time) ................................... 54

i[_ 56 RL10-IIB Engine -- Pumped Idle to Full Thrust Transition

(Chamber Pressure versus Time) ............................................... 54

57 RL10-IIB Engine -- Pumped Idle to Full Thrust Transition

(Chamber Mixture Ratio versus Time) ....................................... 55

'_ 58 RL10-IIB Engine -- Pumped Idle to Full Thrust Transition (Fuel

Pump Speed versus Time) ....................................................... 55

59 RL10-IIB Engine -- Pumped Idle to Full Thrust Transition

\_ ("I_L_e Inlet Temperature versus Time) .o,....oo.,., .eo..o.°.,.oo°ooooo.,. 56

60 RL10 Thrust Control (P/N 2105497) ......................................... 57

61 RL10-IIB Engine Start Transient (Serve Chamber Pressure

versus Time) ......................................................................... 58

62 RL10-IIB Engine Start Transient (Differential Pressure Across

Bypass Valve versus Time) 58

,_ 63 RL10-IIB Engine Start Transient -- Pumped Idle Operating Mode ,_

to Full Thrust Level (Chamber Pressure versus Time) .................. 59

64 RL10-IIB Engine Start Transition -- Pumped Idle Operating Mode

_ to Full Thrust Level (Thrust Cortrol Valve Area versus Time) ....... 59 _

_'j "!

65 RL10-IIB Oxidizer Heat Exchanger -- l_mped idle Performance '°

(Reversed Hydrogen Flow) ....................................................... 60

66 RL10-1IB Engine (Final Baseline) _ Tank Head Idle (THI)

Operating Mode ..................................................................... 61

67 RL10-1IB Engine (Final Baseline) -- Pumped Idle ....................... 62

68 RL10-IIB Engine (Final Baseline) -- Full Thrust Level ................ 63

[

69 RL10-IIB Breadboard Engine - Tank Head Idle (THI)

_ Operating Mode °*o,,,,°.**,*,,°, ,*,*,.,, .... ,,,..,.,o,.,..,.,,.°.,,,o...,..,,o.°.,.. 64

70 RL10-IIB Engine Breadboard Configuration -- Pumped Idle (PI)

Operating Mode ..................................................................... 65

71 RL10-IIB Engine --Gaseous Oxygen Heat Exchanger Geometry (At

Pumped Idle Design Point) ...................................................... 68

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ILLUSTRATIONS(Continued)

72 RLI0-IIB Engine -- Gaseous Oxygen Heat Exchanger (Stage 1

Core) ................................................................................... 69

i

73 RL10-IIB Engine -- Gaseous Oxygen Heat Exchanger (Stage 2

Core) ................................................................................... 70

74 RL10-IIB Engine -- Gaseous Oxygen Heat Exchanger (Stage 3

Core) .................................................................................. 71

75 Single Sample Guarded Hot Plste Test Apparatus Schematic ......... 74

76 RL10-IIB Oxidizer Heat Exchanger -- Pumped Idle Performance

(Reversed Hydrogen Flow) ...................................................... 76

77 RL10-IIB Oxidizer Heat Exchanger -- Stage 2 (Heat Flux Map) .... 77

78 RL10 Cavitating Venturi Valve (CW) ....................................... 79 [

79 Cavit teriBtics ating................................................................................ Ven.%triValve (CVV); S/N B54X-012; Operating Charac- 80

80 Turbine Bypass Valve (TBV) Assembly ...................................... 80

81 Breadboard Turbine Bypass Valve (TBV) Operation; Tank Head Idle

and Pumped Idle ................................................................... 81

82 RL10 Gaseous Oxidizer Valve (GOV) ......................................... 82

83 G_eous Oxidizer Valve (GOV) Operation S/N CDK-1311 .............. 83

84 Oxidizer Control Valve (OCV); S/N BKD-7935 ............................ 85

85 Oxidizer Control Valve (OCV) Operation S/N BKD ...................... 86

A-1 RL10-IIB Off-Design Computer Program Cycle Schematic .............. A-2

A-2 Fuel Pump First Stage Performance Characteristics (Fuel Pump

Efficiency); RL10-IIB Engine .................................................... A-4

A-3 Fuel Pump First Stage Perfor,_noe Characteristics (Head

Coefficient); RL10-IIB Engine ................................................... A-5

A-4 Fuel Pump Second Stage Performance Characteristics (Fuel Pump

Efficiency); RL10-IIB Engine .................................................... A-5

"=_ A-5 Fuel Pump Second Stage Performance Characteristics (Heed

I Coefficient); RL10-IIB Engine ................................................... A-6
Pratt & Whitney

FR- 18046-3

: ILLUSTRATIONS(Continued)

4

Figure Page

_i" A-6 Oxidizer Pump Performance Characteristics (Oxidizer Pump

_: Efficiency); RL10-IIB Engine .................................................... A-6

A-7 Oxidizer Pump Performance Characteristics (Head Coefficient);

RL10-IIB Engine ................................................................... A-7

A-8 Turbine Efficiency Characteristics -- RL10-IIB Engine .................. A-7

B-1 Transient Simulation Flow Schematic -- RL10-IIB Engine ............ B-2

B-2 Operation of RL10-IIB Engine During Tank Head Idle Transient .... B-5

B-3 Heat Transfer Model Simulates Thermal Conditions of Components

: and Fluids ............................................................................ B-8

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TABLES

Tab/e Page

1 Breadboard RL10-IIB Design/Analym Iteration Summary .............. 8

2 RLIO-IIB Engine Cycle Ccnfiguration. Studied _ Preliminary

Analysis Summary .................................................................. 18

3 Compari3on of the RL10-HB Ensine Preliminary Configuration With

the Alternative Confilpzration .................................................... 44

4 RL10-IIB Engine Heat Exchanger Design Fluid Conditions ............ 67

5 Thermal Conductivity Test Results ............................................ 75

A-1 Symbol Usage in Figure A-1 RL10-IIB Cycle Schematic

Nomenclature ....................................................................... A-3

A-2 Main Chamber and Pnmazy Nozzle Heat Transfer Predictions ....... A-8

A-3 Oxygen Heat Excha_ger ......................................................... A-9

B-1 Symbol Usage in Figures B1 and B2 ......................................... B-3

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J

: _" SECTION I

: INTROOUCTION

J

, This report describes the breadboardlow thrust RL10-Im engine which is scheduled for

t testing in early 1984. A summary isalsoprovided of the analysis anddesigneffort which has been

completedto define the multimode thrust concept applicableto the anticipated requirementsfor

" upper stage vehicles in the late 1980s. Baseline requirements wele establkhed early in the

: currentprogramforoperation of the RL10-IIB engine at the following conditiom: 1) Tank Head

Idle (THI) at low propellant tank pressures, without vehicle propellant conditioning or settling

•# thrust, 2) Pumped Idle (PI) at a 10% thrust level for low "G" deployment and/or vehicle tank

' pre_m_tion, and 3) full thrust (FT) (15,000 lb). Several variations of the engine configuration

wereinvestilpttedandresults of the analyses are also included inthis report.

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'. SECTION II

DEFINITIONAND REQUIREMENTS

The RL10-IIB engine (Figure 7) is derived from the basic RL10A-3-3 but has increased

performance and operating flexibility for use in the Orbit Transfer Vehicle (OTV). With a

' nominal full thrust level of 15,000 lb (in vacuum) at a mixture ratio of 6.0:1, and multi-mode

operational capability as shown in Figure 8, the IIB engine is defined as an RL10A-3-3 with the

following changes:

" 1. Two-position eztendible nozzle with recontoured primary section to give a

large increase in specific impulse with an engine installed length of 55

inches.

- 2. Injector reoptimized foroperation at a full thrust level mixture ratio of 6.0:1.

, ! 3. Tank head idle (THI) capabilities, where the engine is run without its

turbopump rotating but pressure-fed on propellants supplied from the :

: vehicle tanks at saturation pressure. Propellant conditions at the engine

L inlets can vary from superheated vapor, through mixed phase, to liquid. The

objectives are to supply low thrust to settle vehicle propellants and also to

obtain useful impulse from the propellants used to condition the engine and

; vehicle feed system.

5 4. Operation at low thrust in pumped mode (maneuver thrust) to provide low ,_

,. AV andautogenoutan s kpressurizaticapabi on lity.

5. Capability forboth H2and 0 2 autogenous tank pressurization. ,:

_' Thrust : 15.000Ib _,

. _ ChamberPressure : 400 psla

_ AreaRatio: : 205

Isp :459.8secat 6.0 MR

55 in. /_ 1! _ffi_ Operation : FullThrust

i, ___ I_._ (SaturatedPropellants)

_' ManeuverThrust

' (SaturatedPropellants)

Conditioning : TankHeadIdle

r'I_CEDING PAGE BLANK NO.I" FI_JCED

":O280478

Figure 7. RLIO-I1B Engine Configuration

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FR-18046-3

Thrust = 100%

I

Propellant

Setting t

and Engine

Thrust _-, 0.8% to 3.5% ',,

Thrust

Tank

Pre-Pressurization

Thrust _ 10%

I

Idle (THI)

Idle (PI)

Time.---

FD 280485

Figure 8. RLIO-IIB Engine Multimode Operation Capability

A. DESCRIPTION

Figure 9 shows an engine flow schematic for the current RL10A-3-3A engine, and Figure 10

for the IIB engine. The fuel pump interstage cooldown valve is deleted, since the engine is

conditioned by running in THI mode. A GO 2 heat exchanger, GO 2 control valve, turbine bypass !

valve and cavitating venturi valve are added to enable the engine to run in THI and PI. Fuel and

oxidizer tank pressurization valves are added to give autogenous tank pressurization capability. ._

Additional solenoid valves and modifications to the oxidizer control valve and thrust control

valve give the engine its capability to operate in three modes. A dual exciter gives improved

ignition reliability in THI. The primary nozzle is recontoured and a jackscrew-operated, twoposition, dump-cooled extendible nozzle is added. The primary nozzle exit diameter is fixed at 40

in., since this is the limiting diameter for the extendible nozzle to be retract,_._,over the engine's

power head, and is also the largest size which allows insta!lation with a truncated extendible

nozzle in P&W/GPD E-6 test stand. The injector is reoptimized to give improved performance at

a mixture ratio of 6.0.

B. OPERATION

1. Tank Head Idle (THI)

The engine is started in THI mode, with propellants supplied in vapor, mixed, or liquid

phases.

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Oxidizer

Flow

Control

Liquid Fuel Pump

Interetage 02

Cooldown

Valve Heat

Uquid Exchanger

H20

Fuel Pump

Discharge

Cooldown

Valve

FD 280486

Figure 9. RLIO-3-3A Engine Flow Schematic -- Current Design Provi 'es Single Thrust

ravel

Oxidizer

Control %? lI,-- Gaseous

Va;v;-_p X Oxidizer

,I

• I •

,ro., [.LI '

Control _ I_l-,urbin. I Exchenger !

Valve H2-__r.

H2 Pressure / '---'-

Relief Valve--/

FD 280487

Figure 10. RLIO-IIB Engine -- GOX Heat Exchanger and Throughflow Control Valves are

Primary Changes

With the inlet shutoff valves open, fuel flows through the pump, the thrust chamber cooling

jacket, around the turbine, through the GO2 heat exchanger, and into the main injector.

Similarly, the oxzdizer flows through the pump, and with the oxidizer control valve shut, all the

flow goes through the heat exchanger to the injector.

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2. Pumped Idle (PI)

! After pump conditioning has been completed in THI mode, the engine is ready to be

it operated thrust. Toitsstpum art pethed turbopu idle thrust mps,level the formainlowfuAVel maneuvers shutoff valveor isas opened, a step onandits the acceler turabtion ine bypass to full

valve is closed momentarily to give a high initial turbine torque and is then reopened to the

maneuver-thrust position. The cavitating venturi is decreased in area to isolate the fuel pump

from jacket bo_ling instabilities.

3. Full Thrust (FT)

The engine is accelerated to full thrust by closing the turbine bypass valve, opening the

liquid oxidizer valve, closing the gaseous oxygen valve, and opening the cavitating venturi valve.

At about 90% of full thrust, the thrust control valve opens to reduce thrust overshoot.

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SECTION III

_.NGINE CYCLE ANALYSIS

The RLI0-1IB rocketenginemulti-modeoperationanalysisand designaddressedinthis

reportwas precededby extensivaenalysisand testing,atlow thrustlevels,ofearlierRLI0 engine

models.Testingon theRL10A-3-2,RL10A-4, and RL10A-3-7 throttlingenginemodelsbetween

1963and 1967resulteind over800enginefiringsand 70,000secondsofruntimeattankhead idle

(THI) and pumped idle(PI)modes of operation.These RLI0 enginemodels requiredactive

controls to obtain moderately stable low thrust operation. The 55 inch long, RL10 Derivative IIB

engine concept, defined in the early 1970s, was required to be caps _ ie of stabi(e operation at THI,

25% PI and full thrust (FT) using an oxidiz2r heat exchanger (OHE) and simple, solenoidactuated engine valves instead of active controls. These analyses of RL10 Derivative II engines,

conducted during the 1970-1973 period, included Derivative IIB thrust chamber heat transfer

predictions, thermal skin OHE performance requirements, definition for stable PI operation at

10% thrust with fixed position valves. Both steady state and transient cycle simulations were i

included in these Derivative Engine Study results as reported in P&W Report No. FR-6011, L

dated 15 December 1973, under contract NAS8-28989. Later analyses were reported in the P&W

Space Tug Engine Report, P&W Report No. FR-7498, dated 21 May 1976 under contract NAS_._-

31151, and an Orbital Transfer Vehicle (OTV) engine study P&W Report No. FR-14615, dat_cl

15 March 1981, under contract NAS8-33657. All of the background data from these, studies were

reviewed for applicability and documentation to prevent duplication of effort during this RL10- _

IIB design and analysis program under NASA contract NAS3-22902.

The evolution of the RL10-IIB engine cycle during this design/analysis program, urder the

Product Improvement Program (PIP), is shown on Table 1. The engine was derived from the 4 ';

RL10A-3-3 engine, and modifications were made as required to satisfy the particular goals and

operating conditions for the RL10-IIB engine. The initial configuration shown, which had been

carried forward to this program from earlier analyses, had a pumped idle thrust level of 25% of _

FT. Table 1 also presents characteristics of the Preliminary Fngine Design, an Alternative

Design, the Baseline Design (which was used for Flight Representative control_, and OHE

performance predictions), and the Breadboard Design intended to be used for the 1st Test Series. i '_

These analyses were required primarily because of the 10% PI thrast-level selected f)r the RL10- J

IIB engine and changes identified by the series of hardware design/analyses.

A. PRELIMINARY CONFIGURATION

Preliminary RL] 0-IIB engiz_e steady state cycle analyses defined the operating characteristics, engine configuration requirements, and control valve requirements at low thrust using

estimated performance for an oxygen heat exchanger at the 10% thrust PI design point identified

at the start of this effort. The RL10 Derivative Engine steady-state cycle deck MF2277 described

in Appendix A was modified to provide the 10% thrust PI sir_ulation #ith estimated heat

exchanger characteristics. Incorporation of a reduced effective flow area (0.9 in. '2)turbine stator

configuration, tested extensively during the 1960s, matched the turbine powel to the required

10% PI flow rates. Engine operation was investigated using propellant inlet conditions

achievable on the E-6 test stand (Fuel Pump Inlet Pressure (FPIP) = 25 psia, Oxidizer Pump

Inlet Pressure (OPIP) = 33 psia) for the scheduled breadboard low thrust test series, as well as

with the lower propellant i,_let conditions (FPIP = 20 psia, OPIP = 20 psia) that will be available

for subsequent low thrust test series. The later propellant inlet conditions are more representative of the expected flight vehicle propellant conditions and will be use_! for the "flight

representative" (FR) component designs and the second engine test series.

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Table 1. Breadboard RLIO-IIB DesignAnalysis Iteration Summary

°_!'_ 02 H 2 Chamber/ Turbine

Injector l_iector Nozzle OHE Nozzle H2/O2

Item Area A_a Heat Heat Area Gear Inlet Applicable

No. Con[iguration (in. _) (in._) Transfer Transfer (in. 2) Ratio Conditions Figures

_' 1 RL10 A-3-3 0.8 2.25 RL10A-3-3 NA 1.1 2.5 NA NA

:I (70 in.)

: 2 Initi RLI0-1IB al PIP 0.8 2.25 RL10A-3-3 Estimated (25% PI) 1.1 2.5 HRepnme ight ntative None

3 Preliminary 1.0 2.25 RL10A-3-3 Estimated 0.9 2.5 Flight 11 t') 32

i RL10.IIB (10% PI) Repreasntative

t

- - 4 Preliminary 1.0 2.25 RL10-IIB Estimated 0.9 2.5 Flight 33 to 37

: Update (55 inch) Representative

RL10-IIB

_ 5 Alternate 3.0 1.7 RL10-IIB Estimated 0.9 2.1 Flight 38 to 44

| Gas/Gas Representative

RL10-IIB

6 Baseline 0.8 2.25 RL10-IIB Estimated 0.9 2.1 Flight 45 to 47

RLIO-IIB Representetive

7 Baseline 0.8 2.25 RL10-IIB 3 Stage 0.9 2.1 Flight 48 to 64

RL10-IIB Update OHE Repr_entative

Update

8 Final 0.8 2.25 RL10-1IB 3 Stage OHE 0.9 2.1 Flight 65 to 68

Baseline Update Update Representative

"reversed flow

9 Breadboard 0.8 2.25 Final Final 0.9 2.1 Breadboard 69 and 70

RL10-IIB Baseline Baseline

NA -- Not Applicable

Parametric analyses of requirements for the PI Gaseous Oxidizer Valve (GOV) area and

oxidizer injector temperatures as functions of venturi pressure loss _nd mixture ratio are shown

in Figure 11 for the breadboard test series inlet conditions. As indicated, marginally acceptable

valve differential pressures (AP's) and oxidi_r injector conditions could be obtained with the

! 0.8 in.2 RL10A-3-3 Bill-of-Material (BOM) oxidizer injector flow area and 2.5 gear ratio.

However, increased GOVAP wouldbe available with the oxidizer injector flow area increased to

1.0 in.2

Using the flight-representative inlet conditions showed that PI operation with the 0.8 in.2

oxidizer injector area would require a gear ratio change to 2.1 tJ provide acceptable GOV _P

(Figure 12). The 2.1 ratio gears hadpreviously been tested on the RLIOA-4 engine. Increasing

the oxidizer injet area to 1.0 in.2not only increased the control margin, it also provided 

satisfactory oxi6i_ferinjector conditions andcontrol valve AP with the 2.5 gear ratio at the flight

representative in;et conditions as shown in Figure 13.Incorporatingthe 2.1 gearswould increase

GOVAP margin mrther as indicated. However,the 2.1 gear parts were long-lead items and none

were available, so continued analysis was concentrated on the 2.5 gears and 1.0 in.2 injector

configuration. The 10% *hrust operating points at mixture ratios of 4.0, 5.0, and 6.0 were

comparedon RL10 pump _peratingmaps with test data points (development engine FX141-45)

'm
v

Pratt & Whitney

FR-18046-3

obtained uringlowthrustestinigt.1966a:_!.:','ksshown inFigures14and 15,thetestdata

indi_,tethatthereshouldbeno problemwithtu..'_i:m:_p stability.

Steady-stateTHI operationwith theflig_:-.:presentatfiuvelpump inletconditionsc "

preliminaryvalveareasindicatethd atthe ...../'t/.,wmould requireundesirablthe ro.ttlitong

,rg'idea tin'gemixt t ureratio f4.0with_;;•..,,'._z,:,_zerpump inletpressure.Witl.•:dveareas

':_J _t totheplannedwideopen posit_:. ' 3V l_v ---2.0in.2and GOV ACD --1.273in.2),

mLZt_reratiostabilizaetd3.3(FigureJt.q't

The RLi0 _IB engine _._)nfi_r," ._ .. ;_ completion of the preliminary analysis is summ_Jtired as item 3 i_ Table 1. Valve s, _.:, .J,d flow schematics for engine conditions corresponding

to the three required operating l,-:':_.!_J(THI, PI, and FT) are shown in Figures 16 through _8. A

comparison of configurations stt_di_:d during the preliminary analysis is presented in Table 2.

Transient analyses were con(',ucted with the computer programs defined in Appendix B

using this preliminary engine configuration t_) provide data for the flight-representative control

valve designs The transients from start to THI, from THI to PI, and from PI to FT were each

examined separately. The start-to-THI transients were evaluated with flight represent-.tive inlet

pressures and a combination of both saturated li,?dd and saturated var_r propellants.

Preliminary THI transient engine characteristics with satura_:_ I;_,,;,__:,_oeflants are shown in

Figures 19 through 22. As indicated, stJ._ady-state THI operation is achieved in less than 45

seconds after start. Preliminary engine characteristics for transient operation from THI to PI

mode were also generated and critical engine parameters are shown in Figures 23 through 25.

Steady-state PI operation is achieved in less than 1 second after initiation of the transient,

as shown.

Preliminary RL10-IIB engine transient characteristics from PI (10% thrust) to FT were I

also defined. Initial engine transient valve scheduling required that the simulated RL10 thrust

control valve (TCV) stay closed up to 300 psia chamber pressure, which is normal operation.

This required the turbine bypass valve to be ramped closed very slowly (-- 806 msec-- an

unreasonable requirement) to ivcrease duration of the transient _nd prevent pump overspeed.

Transient characteristics with a more reasonable TBV ramp tim_ (_ 200 msec) produced an

acceleration with unacceptable pump overspeed and thrust overshoot (denoted as squares 9n

Figures 26 through 29). Opening the TCV at a chamber pressure of 100 psia produced a more

acceptable transient (denoted as circles on the figures). The complete transient characteristics

were not defined during thi_ preliminary analysis and the simulation was arbitrarily terminated

when chamber pressure reached 300 psia. The selected valve sequencing and flow rates for these

*.ransients are presented in Figures 30 thtuugh 32.

B. PRELIMINARY UPDATE CONFIGURATION

An update of the preliminary RL10-IIB engine cycle analysis incorporated results of the

thermal analysis of the recontoure£ _nd shortened RL10-IIB thrust chamber/primary nozzle

assembly. The new heat transfer characteristics were incorporated into the cycle deck and new

design points at THI, PI, and FT were generated. Flow schematics are shown in Figures 33

through 35. Pumped idle (10% thrust) operation at a mixture ratio e¢ 6.0 required a r_uction in

cavitating venturi pressure loss (Figure 36) to provide the desired conditions at the oxidizer

injector. Control capability on the oxidizer side was diminished because the GOV pressure loss

was decreased by 30%. Control capability would ha_,e been reduced further at lower mixture

ratios as it would have been necessary to further decrease the venturi pressure loss to maintain

gaseous conditions at the oxidizer injector.
]

Pratt & Whitney

t FR-18046-3

240 ';; Oxidizer P ,O/r =6.0 220 -- L

;I Injector O/F=4.O'_ __ _ _ "_

i Temperature - _,_ I

:t ° R 20b - ,,,, InletConditions

i*i F'mlInk_Pre t _,,re pr;) ,, 25 psi',

180 I NetPoultlvQSuctionPr_t_u,rAINP == 4.5 p_Id

OxidizerInletPressure(POil • 33 plda

.4 0.8 "_il NetPositiveSuctionPressure(NPSP) = 10peld

"°i O/FL4.0_ 2.5:1C_r RltJo

i ',,..o_:-5.0 / ox,._ ,._or

Turbine _%_ L _ 1'0 In.2

Bypass _%._,_ --_'_-- 0.8 In,;=

Valve Effec(tive TBV) 0.7 .... -_,%

Area (Aco) _/F-O.O

| " In.Z 0.6 -%J _%%,

1.8

0/I:-4.0 _ _ t

=I= GOV 1.6 1.,; _ O/F=_6.O__

-I EffArecetive a _

('_o) - in.= 1.2

\ "\ ,\ \ \

1.o _

0_8

20 _ PropellantMixtureRatio(O/F) = 4.0 5.0 6,0 m

/ '

.._u, ,o // / "

VaOxidizer J //4 MinimumA p, lve(GOV), /

O,,.r..t,a, ,,,\\__\,,\\\\\,,,\\\\\\\) _(\\\\\,,_¢,\)_\\ _\\\\,:,_ Pr==re I .

(&P) - psld 0 / I P"

/ / /

/ /

/ /

-10 - •

0 10 20 30 40 50 60

Cevltatlng Vonturl Valve (CVV) Presst,re Loss - p,_ld

i-j Figure 11. RLI_/-IIB Engine O_mtion _t Pumped Idle (Bre_Iboard Test Series

Inlet Condition_)

10

, q O_;C _]_

T _ r
Pratt & Whitney

} FR-18046-3

]

-i

i

i 240

:! 6.

._l Oxidizer

Injector %=

Temperature - 220 --O/F = 4.0 5.0-

2o0 • , --

Inlet Condltlonl

0.8 _ Fue_ Inlet Pressure (PFI) = 20 pill -

' )/F_4,0 Net Polgtlve Suction PreSsUre (NPSP) • 2 pskl

Oxldlz_ Inlet Pressure (POI) = 20

i Turbine Net Po_tlve Suction P_re (NPSP) • 2 psld

m

:i

;r Valve (TBV) 0.7 '%.,

t Effective

-! Area (Aco)

4 " In'i

"4 ,---- 2.1:1 Gear Ratio !

' 0.6 • 2.5:1 Gear Ratio

Oxidizer Injector Effective Area = 0.8 in.2

; 2.5

-!

'i

.

i GOV 1.5

Effective

| Area

I (AcD) . in.2 1.0 O/F -- 4.0----5.0----6.0-

0.5

4

0

Gaseous Mixture Ratio (O/F) = 4.0 ,_

Oxidizer .j_ Minimum & p

Valve(GOV) 0 "////,'//// ///I//////,#lP'Z7,777_. , y//////,, _////t

Differential [ _" f'

I

Pren,_re

(Ap). peld • •

-20 ....

0 10 20 30 40 50 60

Cavltatlng Venturl Valve (CVV)

Pressure Loss - psld

FD 278888

Figure 12, RLIO-IIB Engine Operation at Pumped Idle (Flight-Representative

- Inlet Conditions)

|

,

()S93(" 11 (_
Pratt & Whitney

FR-!8046-3

250 Bill-of-Materials Heat Transfer -1

17k Turbine (9 Plugs)

Oxidizer In I)ctor Effective Area (ACD) = 10 in 2 I

_ 6 _0 . _ - GearRati°= 2"1:1

230 -,,,- ,,, Gear Rmtio = 2.5:1

Oxldlzer Injector _ •

Temperature- °R _ • k

50 %%

210 _ |_'_ %%

OIF=4 0 tt

190 Inlet Conditions

Fuel Inlet Pressure (PR) = 20 I)ala

08 "_= Net Po_tlve Suction Pru_re (NP. - 2 paid

"_ ,= Oxidizer Inlet Pre_ure (POI) - 20 petm

• "•%,. " Net Positive Suction Pressure (NP= - 2 paid

_' ! Turbine Bypass O/F,=4 0

i Valve0BY) 07 5_ ._..-- ]

Effective Area _""'2

"; (ACD) " in.2 t,,,,,, """"•,

06 _ 1

2.5 l

I

20 I _. % %

"b

• % •

Gaseous Oxidizer 1.5 % %'%" %

Valve (GOV) _._ •

Effective Area 1.0

(ACD) . in2 O/F--_ 0 50 6.0

05 I " 0

3O I [

20 Propell Mixtureant (O_/F) 4.0 .j... 5.0_ ," .-"

Gaseous Oxidizer Ratio

Valve (GOV) 10 I ,

Differential Pressure . '°'°"J ,o°' Minimum &P

(Ap) . psld 0 ,////_ //////// ////////.,///_.-///_ ,-,-//_/j/ ,////11/

-10 0 10 20 30 40 50 60

CavltGllno Venturl Valve (CW)

Pressure Loss - paid

FD 278889

Figure 13. RLIO-IIB Engine Operation at Pumped Idle (Flight Representative Inlet

Conditions, Increased Injector Area)

1

t

_! 12 :

i

(i'l) '

_93('
s Pratt & Whitney

' FR-18046-3

4C0 Oxidizer Injector Effective Area = 1.0 In.2

_ Development Englnr_FX141-45 EnginJe 10% Thrust; Mixture Ratio (O/F) = 6.0; DerivatJ_'ve

10% Thrust; O/F = 5.0

10% Thrust; O/F = 4.0

Shaded Data Points = 2.1:1 Gear Ratio 18,000 rpm

Unshaded Data Points = 2.5:1 Gear Ratio

l

/ 7

16,000 rpm

_--i /

' ', Fuel Pump

Pressure

Rise - psid 14,000 rpm

200 _"*"'--

/ -

i

I

_ __ rpm

0

:' 0 0.5 1.0 1.5 2.0 2.5 3.0

•" Fuel Flowrete- Ib/sec

FD 278890

r

'_ Figure 14. RLIOA-3-3 Fuel Pump Operating Characteristics

t
Pratt & Whdney

_ FR-18046-3

!

209 I Oxidizer lanjector Effective Arq_ :'1.0 In. 2I

I @__71_ rpm

"' 180 _

Q Development Engine FX141-45

" Z._ 10% Thrust; Mixture Ratio (O/F) -, 6.0; Derivative Engine

160 _ 10I(P%_ ThThrrust; ust; O/ O/FF == 5.0 4.0 " -'_ I

Shaded Data Points = 2.1:1 Gear Ratio ] .

Unshaded Data Points = 2.5:1 Gear Ratio I 141

_, _- ,----,,,-,-- "_00 rpm

!

120 -

®

Oxidizer Pump

Pressure 100

Rise - psid (_ 5000 rpm

80 C Q ,

60 - mm--(_ _ _ 4000 rpm

4O ®

m_

-- - _ 3000 rpm

20

t

0 , I

0 2 4 6 8 10 12 14 I*

Oxidizer Flowrate - Ib/sec i

i

I

FD 278891 I

Figure 15. RLIOA-3-3 Oxidizer Pump Operating Characteristics t

14

(}w);l('


' Pratt

& Whitney FR-18046-3
t4"

Pratt & Whitney

< FR-18046-3

Table 2. RLIO-I!B Enginc Cycle Configurations Studied -- Preliminary Analysis Summary

Con[i_,uration Number

l 2 3 4 5 6

Flight Flight Flight Flight

Inlet Conditions* Breadboard Breadboard Representative Representative Representative Representative

Gear Ratio (H2/O 2) 2.5 2.5 2.5 2.1 2.1 2.5

Oxidizer Injector 0.8 1.0 0.8 0.8 1,0 1.0

AcD-- in. 2

Turbine Stators 0.9 0.9 0.9 0.9 0.9 0.9

ACD- in. 2

Acceptable Gaseous

Oxidizer Valve (GOV)

Characteristics Marginal Yes No Yes Yes Yes

*Breadboard -- Fuel Pump Inlet Pressure (FPIP) ffi 25 psia Net Positive Suction Pressure (NPSP) = 4.5 psi

Tests

, -- Oxidizer Pump Inlet Pressure (OPIP) = 33 psia Net Positive Suction Pressure (NPSP) = 10 psi

Flight -- FPIP ffi 20 psia NPSP = 2.0 psi

Representative

, Tests

-- OPIP = 20 psia NPSP = 2.0 psi

.

t

T.

_i 18

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Pratt & Whitney

_ ' FR-18046-3

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Pratt & Whitney

._ FR-18046-3

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FR-18046-3

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2

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Pratt& Whitney

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& Whitney

FR-18046-3
!

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,! FR-18046-3

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,_ °_

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_ 25
:\ Pratt & Whitney

FR-18046-3

360 I I I ,

320 --- TBV Ramp Time I _ 200 msec, TCV

Opened at Pc= 100 psia

Chamber 200 _r

Pressurepsla 150

120 [_

:' o I

:.. 0.0 0.05 0.10 0.15 0.20 0.25 0.30 0.35

_ Time from PI to FT Slgnal- Seconds

FD 278902

Figure 26. RLIO-IIB Engine Transient -- Pumped Idle Mode to Full Thrust (Chamber

Pressure versus Time)

I I I I

_] TBV Ramp Time _ 200 msec _ // 40,O00

TBV RampTime _ 200 msec, TCV r-_

Opened at Pc= 100 psia _ r

L_

=ooo

FuelPump

Spe<_d- rpm 24,000 _.

"; 16,000

8,000

0.0 0.05 0.10 0.15 0.20 0.25 0.30 0.35

Time From PI-to-FT

Signal- Second

FD 278903

; Figure 27. RL!O-IIB Engine Transient -- Pumped Idle Mode to Full Thrust (Fuel Pump

: Speed versus Time)

l

26

• !
Pratt & Whitney

FR-18046-3

9

i w [_] TBV Ramp Time _ 200 msec

t 8 -(_ TBV Opened RampatTime Pc = _10020psia 0 msec, TCV

i 7 i , ,

L 6

: I Chamber 5

Mixture _ S

Ratio 4

2

-i 1

i o t 0.0 0.05 0.10 0.15 0.20 0.25 0.30 0.35

" _ Time from PI to FT Signal - Seconds

F'I;278904

Figure 28. RLIO-IIB Engine Transient _ Pumped Idle Mode to Full Thrust (Chamber

Mixture Ratio versus Time)

640 _ _ iI

620 _ i

600 [_

TInlet .r_.,.5.. o -_ _,. ,

Temperature- 560 _

oR

.- 540

_TBV Ramp Time --- 200 msec

520 -- (C)TBV Ramp Time _ 200 msec, TCV

Opened at Pc = 100 psia

; 500

480 '-

0.0 0.05 0.10 0.15 0.20 0.25 0.30 0.35

Time from PI to FT Signal- Seconds

FD 278905

Figure 29. RLIO-IIB Transient -- Pumped Idle Mode to Full Thrust Level (Turbine Inlet

Temperature versus Time)

I

,}i ,,
L'.,

Pratt & Whitney FR-18046-3

28

I)_);I ("

.......... _ _ %,* "_ l
Pratt & Whitney

FR-18046-3
%:.

Pratt & Whitney

FR-18O46-3

= 30

I
, Pratt

& Whitney FR-18046-3
Pratt & Whitney

FR-18046-3
Pratt & Whitney

FR- 18046-3
' Pratt & Whitney

FR-18046-3

230

Oxidizer Injector 220 210 "'"" ""-....,,,,,,.,,,..,,,, ' _"___'__....,.,.

: Temperature'°R 200 - Fuel ,nletlnlet ConditiOnSpremsure (PFI) = 20 psla """'U'"''"..,,._[l'"'""

190 - Net Positive Suction Pressure (NPSP) = 2 psid

Oxidizer Inlet Pressure (POI) = 20 pal=,

0.7 - Net Positive Suction Pressure (NPSP) = 2 )eid

_QQQ _

_" Turbine eypaem

_ .; Valve Effective 0.6

; Area (Aco) - in.2 Q Old Design Point """"'%,,.,,,.

t [] New Design Point

i o.s --,---- Bill-of-MJeterials Heat Transfer

. ; ..... Revised Heat Transfer

2.5 " _

t

2.0 %,, \

Gaseous Oxidizer "%,,. Valve (GOV) 1.5

Effective Area Mixture Ratio = 6.0 "-_J"......,....,

_ 17k Turbine (9 Plugs) ._

(AcD) " In'2 1.0 Oxidizer Injector Effective Area = 1.0 in.2 .........

Gear Ratio --- 2,5:1

0.5 ' '

25

B°

2O

OO•B

Gueous Oxidizer 15 d_'•*

Valve (GOV) •,,"

Differential Pressure 10 _ ,,-*"" .

(&P)- psld ,[-_"

5 ,oooOOOo_- J j_o' , ,

030" 35 40 45 50 55

Cavltatlng Venturl Valve (CW) Pressure Loire - paid

FD 278912

Figure 36. RLIO-IIB Engine Operation (I0% Thrust Level)

34
k:,

Pratt & Whitney

FR-18046-3

C. ALTERNATE GAS/GAS CONFIGURATION

At this zmii_t i: the ,analysis a change in the engine's basic flowpath was investigated. The

engine,in its_relwinaryconfigurationutili , zesthe oxygen-hydrogenheat exchangerin the

turbinebypassi_owpath(Figure37)tovaporizetheliquidoxygenatlow thrustlevels(<10%),

thusprovidingade_luatinj e ectoprr essurelosstoensurestablecombustion.Duringacceleration

i toFT, closingtheGOV causestheoxygentobe routedthroughtheOCV totheinjectowrhere :l

_ sufficient i_je:tor differential pressure (Ap) is available for stable operation at FT. However, a

i portion of the prdiminary engine acceleration range (between 10% and 40% thrust) may have

i insufficieinje n_ cto(rliquidoxygen)Ap topreventcombustioninstability withtheGOV closed.

'_ Therefore, an _lt_rnative configuration was conceived to eliminate this possibility. The heat

i exchanger was moved to the fuel le.g downstream of the main shutoff valve (Figure 38) so that )

bo_h propellants ';'lowthrough it at all times, thus ensuring sufficient oxidizer injector AP and

pote,zt;ally allowing stable engine operation throughout the range from 2% to 100% thrust. l

.I This configuration change would eliminate the liquid oxidizer flow control valve. Ground

i ratio trim and utilization capability would have to be added to the mixture propellant gaseous

t oxygen valve (GOV). Then, to accommodate the full thrust (FT) gaseous ozyge:l flow, the injector's effective area would have to be increased. Initially, an area of 2.0 in. 2 was nvastigated,

i butthisarearesulteidna marginalfuelpump stalmlargin.Thereforeto, increasef_Jelpump stall

margin,theareawas furtherincreasetod 3.0in.2To maximizecozrbustoerfficiencthy,evelocity

of the gaseous hydrogen into the chamber was also increased to match the velocity increase that

resulted from gaseous oxygen injection at FT. This was achieved by decreas:ng the fuel injector

effective area by approximately 25% to 1.7 in. 2To ensure adequate pressure loss on the oxidizer

j side(forcontrolpurposes)and tomove thefuelpump operationaway from thestalline,the

I H2/O 2 pump gear ratio was reduced from 2.5 to 2.1. Pump operating parameters at 10% thrust

level are presented in Figures 39 and 40. The effects of varying the mixture ratio and cavitating i

venturiAP on the 10% thrustoperationareshown in Figure41.Engine cyclepointsforthis i

alternative (gas/gas) configuration are shown in Figures 42 through 44. Table 3 compares the |

preliminary configuration with this alternative configuration. ."

D. BASELINE CONFIGURATION

A proposal to build the alternative configuration for testing was rejected because of the

significant changes to engine hardware and operations experience not related to low thrust i

requirements, however the option to implement it later was left open. The same oxygen-hydrogen

heat exchanger design requirements apply to either of the low thrust engine configurations. The

2,1:1 gears, however, offer benefits to both the gas/liquid and gas/gas versions of the engine, so a

decision was made to incorporate the gears into the gas/liquid engine. These gears also allow the

oxidizer injector area to be re_luced to 0.8 in. 2 -- the same area as in current RL10A-3-3A

production engines. Flow schematics for the resultant "baseline" engine configuration design

points at THI, PI, and FT are presented in Figures 45 through 47.

E. UPDATED BASELINE CONFIGURATION

Cycleanalysiswas continuedwithupdatedcomponent operatingcharacteristiascsengine

designdatabecame availablfoe rthecurrentRL10A-3-3A productionengineand theRL10-11B

engine.Incorporateidntothe steady-statecycledeck were:updatedRL10A-3-3A turbopump

performancecharacteristicrevi s, sedpredictionsfor the 55-inchRLIG-IIB thrustchamber/primarynozzlecharacteristics and,heattransferand flowcharacteristics fortheRL10-11B

engine3-stageoxidizehreatexchanger(OHE), suchas shown inFigure48.The resultantcycle

data are shown in Figures49,50, and 51 forTHI, 10% thrust,and FT operatinglevels,

respectively.

35

....... ; 0m$C
Pratt & Whitney

FR-18046-3

"_ 36
Pratt & Whitney

FR-18046-3

I

37

'1
Pratt & Whit.ey

FR-18046-3

I

1]

(_ Development Engine FX141-45

• _ 10% Thrust; Mixture Ratio (O/F) = 6.0; Prelim_nary "ngine

" 400 _ 10% Thrust; O/F _ 5.0; Pre;Imlnary Engine, ,

II_.J Altern 10% Thrust; at've Conf O/Figura= t4ion.0; Preliminary Engine

Flagged Data Point = 2 in.2 Oxidizer InJe__.orArea

Unflagged Data Point = 3 in.20xld:zer Injector Area

Shaded Datr Points - Gear natlo = 2.1:1

Unshaded Data Points -- Gear Ratio = 2.5:1

or Effective Area = 1.0 In.2

re (PFI) = 20 psla

300 / Net Positive Suction Pro.cure (NP'SP) = 2.0 poid

#4" Oxidizer Inlet Pressuro (POI) = 20 ps_a== j" Net Positive Suction Pressure (NPSF_ 2.0 psid

- psld t rpm

!1 _ _ 10,o_rprn

"-- _ rpm

0

I 6,00 rpm

0 9.5 1.0 1.5 2.0 2.5 3.0

Fuel Ro_Tate - Ib/sec

FD 27Se15

Figure 39. RLIOA-3 3 Fuel Pump (2-Stages)

38
' Pratt & Whitney ,j

ii (__ Development 10% Thrust; MIx Engine htre FX1 Rqtl4o1-

(45O/F) = C_xidi=ar Injector Effective Area (AcD) = 1.0 in.2

,! 6.0; Preliminary Engine Fuel Inlet Pressure (PFI) = 20 psia

f 10% Thrust; O/F = 5.0; Preliminary Engine Net Positive Suction Pressure (NPSP) = 2.0 paid

• _ _ 10% Thrust; O/F = 4.0; Preliminary Engine Oxidizer Inlet Pressure (POI) = 20 pale

I_ Alternative RL10-11BConfiguration Net Positive Suction Pressure (NPSP) = 2.0 psld [

Flagged Data Point = 2.0 In.2

t,, 200 Unflaw=_edData Point = 3.0 in.2 I

Shaded Data Points - Gear Ratio = 2.1:1

Unshaded Data Points - Gear Ratio = 2.5:1

: _ 7000 rpm

180

i 7

160 1

i

_I 140

., 6000 rpm

J

i

-_ 120 w

O

Oxidizer

Pu -_

Pre_sure 100 JI,

Rise- (_ 5000 rpm

psld _

.o _D_0

60 I _ "-'_ _ -- 4000 rpm

• []

0 40

. _ 3000 rprn

20

00 2 4 6 - 8 10 12 14

Oxidizer Flowrate - Ib/sec

FD 278916

Figure 40. RLIOA-3-3 Oxidizer Pump

3_

- i(2)
|

Pratt & Whitney

FR-18046-3

550

i

6.0

5OO

OxidizerInjector

Temperature- °R

450 --'

ii ill

5.0

400

O/F = 4.0 10% Thrust Level

b _ Gear Ratio 2.1:1

.60 ' ='

i Turbine

Valve(TBV) .55

! Effective

l; Ar.(Aco). in.' O/F=4"0_" ___ " __. _

1

1

t 1.75 _.

!

GaseousOxidizer 1.50

AreValve a (,_Effective co)" in.2 ,_0 %_

1.25 _

i 1.oo .... -'_L.

_ _e RaUo(O/F)= 4.0

b

40 _ ,,.,'_.0

_o ,/ / /

GaseousOxidizer ._ j j,v

Valve Dlfferentlal OIF = 4.0

Pressure(&P) - paid ._"

20 f

10 10 20 30 40 50 60

CavltingVenturi Valve (CVV)

DifferentialPressure(&P) - psld

"_i-- Figure 41. RLIO-IIB Alternative Configuration Cycle Deck Results

40

1 -'" w ...... (_)
t

Pratt& Whitney:

FR-18046-3

1
Pratt

& Whitney

_,; FR-18046-3
Pratt & Whitney

FR-18046-3
Pratt & Whitney

FR-18046-3

Table 3. Comparisonof the RLIO-IIB Engine Preliminary Configuration With

the Alternative Configuration

Preliminar_ Alternative

Operating Range -- % Full Thrust 2 to 10, 40 to 100 2% -- 100%

Oxidizer Control Valve Yes No

Gear Ratio 2.5 2.1

Fuel Injector Area -- in.2 2.25 1.7

Oxidizer Injector Area -- in.2 1.0 3.0

GOX HEX Used -- % Full 2 to 10 2 to 100

Thrust

Start Transient Rapid Pc Rise Smooth and Clean Pc

at GOX-to-LOX Point Rise With Constant COX

° •
Pratt & Whitney

FR-18046-3
J Pratt

& Whitney

_ FR-18046-3 "i

/

1 Pratt & Whitney

,_ FR-18046-3

i. Hydrogen Exit

', _f Tout" 238°R

" _ _ Pout" 46.4 psia

i Stage 1

" _ Oxygen Inlet

T_ ,, 167.30R

f' Pi," 84.3 psle

m- 2.84 Ib/Nc

Hydrogen Inlet

Tin " 639°R

P_- 47.1 psle

{n-. 0.182 Ibm/Nc

Oxygen Exit Stage 3

Ta,_ - 209OR

Pout- 77.2 p_a

Figure 48. RLIO-IIB Engine Oxidizer Heat Exchanger Per[ormanee Data -- Pumped Idle

_ Mode

o

48

OIII_C ®'"i

Pratt & Whitney

FR-18046-3

5O

l_:t('

®
Pratt & Whitney

FR-18046-3
Pratt & Whitney

FR-18046-3

? '

: A subroutine that approximates the thermal ine,tia of the OHE was then incorp_.rated into

the engine transient compute: _.:,nulation. The model incorporates the effects on propellan_

temperatures of the heating or .ooling of the mass of metal i, the OHE. The one-dimensional

model of heat flow to and from the metal is based on a multi-point analysis -f the he._t exchanger

at steady-state conditions. Use of the model _ves a more realistic representation ol transient

parameters. Transients were investigated from THI to PI. Significant engine parameter_ (Pc,

O/F, rpm, and FTIT vs time) are shown in Figures 52 through 55. The transient from PI to ler

was also investiga_<i to determine valve _heduling. The program wa_ run with ramped input

thrust control characteristics b_cause an _ccurate thrust control transient simulation was not

available. Figures 56 through 59 present the same engine parameters listed above versus time.

This acceptable transient was achieved by opening the cavitating venturi and n_dn fuel valve,

allowing the engine to accelera*e to an intermediate thrust level (Pc _ 160 psia) then clo_ing the

turbine bypass valve. Thi-_ allowed the gaseous oxygen downstream of the (liquid) OFC t_ be

removed from the system before the transition to ful_ turbine powe_, thus preventing the

: excessive fuel pump ove_peed seen on previous transient simulations. (c.f. Figure 27,

Preliminary RL10-IIB Configuration.)

t

,_ 45 "

- 40

?,_ 30 /

Chamber 25 I

Pre_murei

psla 20 f

10 _ --_,_ -

5

0 J i

I

• 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Time from THI to PI - Seconds i

FD 278928

Figur_ 52. RLIO-IIB Engine -- Tank Head Idle to Pumped Idle Transition (Chamber i

Pressure versus Time)

52

®
: Pratt & Whitney

FR-18046-3

7.5

7.0

6.5

Chamber5.5 .o _ _

Mixture

R_.tio 5.0 _ / _,,,,,,jj

,.ovl/

"i 3.5

3.0

= 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0,7

Time from THI to PI Signal- Seconds

FD278929

Figure 53. RLIO-IIB Engine -- Tank Head Idle ro Pumped Idle Transition (Chamber

Mixture Ratio versus Tirrr_)

18,000

16,000

14,000

12,000 L

Fuel /

Pump 10,000

Sp_d- 8,1;cO rpm

6,000 /

4,000 f

- /

2,o0oo _._1/ 1

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Time from THI to PI Signal- Seconds

FD278930

Fi/,_ure 54. RLIO-!IB Engine -- Tank Head Idle to Pumped Idle Transition (Fuel Pump

Speed versus Time)

'T 53

_j_jj (b_q,IC
Pratt & Whitney

FR-18046-3

675

670

665

660

Turbine 655 f__

Temperature ,n. -

oR 650 __

645 _"

640

635

630

_" 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Time from THI to PI Signal - Seconds

FD 278931

Figure 55. RLIO-IIB Engine -- Tank Head Idle to Pumped Idle Transition (Turbine Inlet

Temperature versus Time)

450

400 v

350 t'_/"-

Chamber 250

Pressure

-psla 200

150 #

lOO

50 ]

: o I

: 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Time From PI-to-FT

Signal - Second

;, FD 278932

Figure 56. RLIO-IIB Engine -- Pumped Idle to Full Thrust Transition (Chamber Pressure

versus Time)

54
l

_ Pratt & Whitney

'! FR-18046-3

",

t

_- 9

, 8 L

7 "

S

6 _ -f

Chamber 5 "'

Ml,_lure fr_ /

• Ratio 4

_ 2

; 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

:_ Time From PI-to-FT Signal - Second

FD 278933

Figure 57. RLIO-IIB Engine -- Pumped Idle to Full Thrust Transition (Chamber Mixture

•; Ratio versus Time)

36,000

Fuel Pump 20,000 L.,

Speed - rpm f

/

12,ooo.j

4,000

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Time From PI-to-FT

Signal - Second

, i

• t FD 278934

Figure 58. RLIO-IIB Engine -- Pumped Idle to Full Thrust Transition (Fuel Pump Speed

i! versus Time)

55

l_3('

®i
Pratt & Whitney

FR-18046-3

_u

° \ 520 Turbine Inlet

• ,_ Temperature °R 480

440 _--

40O

360

320

--- 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Time From PI-to-FT

Signal- Second

FD 2711e36

Figure 59. RLIO-IIB Engine -- Pumped Idle to Full Thrust Transition (Turbine Inlet

. Temperature versus Time)

An effort was made to write a thrust control simulation for use in the RL10-IIB engine

transier.t program. The RL10 thrust control valve (TCV) (Figure 60) limits thrust overshoot

during engine start and controls turbopump power to maintain chamber pressure at steady-state.

A spring-mass model and a two-volume dynamic model were combined to simulate the transient

; response of the thrust control. The spring-mass model de_rmines the shear orifice and bypass

valve displacements as functions of time and fluid system driving forces. The two-volume fluid

- dynamics model calculates flows and pressures in the thrust control to determine those forces.

Various iterations of the thrust control si.nulation _ _n with input engine acceleration

test data from P&W experimental engine FX143-33 (Rm, -. 436.01), which had been fitted

with high response instrumentation to measure TCV input parameters. This produced thrust

control simulation results that compared faro, ably to engine test data (Figures 61 and 62).

However, when this simulation was used with the RL10-IIB engine transient program, unstable

operation was indicated during engine acceleration to full thrust from pumped idle. Many

i__rations of the basic thrust control simulation ar n a simplified version failed to provide either

engine operahon consistent in all respects with measured data or stable engine operation after

acceleration. ,4 modification to the engine simulation to incorporate a gas venturi between the

fuel bypass tee and turbine inlc _ appeared to reduce the chamber pressure oscillation duration

but did not eliminate it entirely (Figures 63 and 64). Since rated thrust demonstration was not a

primary goal of the first test series, the TCV simulation effort was terminated.

- ® r*- • J J..._mmml
Pratt & Whitney

FR-1_)46-3
Pratt & Whitney

FR-18046-3

d "

7OO

A! ' 600 El

•,,,,-- Calculated _

5OO •---- Measured E

!

Servo 400

Chamber

Pressure

" -pals 300 ....

zoo J

= ]

,, _I I I.._

.,-- _-...... T I

r - 0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2

Time after EnglneStert-Seconds

FO2781137

Figure 61. RLIO-IIB Engine Start Transient (Servo Chamber Pressure versus Time)

200

,,--,-- Calculated

....- Measured

100

Differential Pressure(&P) _:_

Across Bypass 0 _ ... . -:__

Valve _- -

\

- 100 _J_ [

-2OO _

0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.6

.. Ti,_e after EngineStart-Seconds

FD 278938

Figure 62. RLIO-IIB Engine Start Transient (Differential Pressure Across Bypass Valve

versus Time)

58 t

089;1("
Pratt & Whitney

FR-18046-3

400 _ Wlth Gas Ventud -_t

30O

Chamber /

Pressurep=a

2OO

J,

00j 0.2 0.4 0.6 0.8 1.0 1.2

Time From EngineSt_,'t Signal- Seconds

FD278939

Figure 63. RLZO-IIB Engine Start Transient -- Pumped Idle Operating Mode to Full

Thrust Level (Chamber Pressure versus Time)

0.35 _']'='_ 1"_ (_i r'

0.30 F(_I With Without GasGasVeflturl Venturl ]l II i

,I, °-oValvetr.,oO.,o II ill

,_ Area.ln.2 0.15 I I'I[ _/ _'1 4TI,*''

0.10 ! --v

0.05 J

0.0 _ t _

0.0 0.2 0.4 0.6 0.8 1.0 1.2

Time from EngineStart Signal- seconds FO278940

Figure 64. RLIO-IIB Engine Start Transition -- Pumped Idle Operating Mode to Full

Thrust Level (Thrust Control Valve Area versus Time)

I F. FINAL BASELINE AND BREADBOARD CONFIGURATIONS

After the designs of the flight representative controls and the design and heat transfer

analyses of the OHE were completed, the characteristics of the "reversed" flow OHE model

(Figure 65) were incorporated in the cycle deck. As explained in Section IV, and Appendix C, the

r^verse flow concept permitted reduction in 3rd-stage heat transfer without redesign of the heat

I 59

- ®
r

Pratt & Whitney

FR-18046-3

exchanger. This became the final configuration. The results are shown in Figures 66 through 68.

The cyc._edeck was then run with propellent inlet conditions and corresponding valve settings

planned for the breadboard lcw thrust engine test program. These results are shown in Figures 69

and 70.

Mixture Ratio (O/F) = 6.0

,. Stage 2 InsulationConductivity= 0.033 Btu/ft-hr°R

t

Hydrogen Inlet

To= = 639OR

: Pout= 47.1 plfla

Oxygen Inlet Stage 1 _- '/ Oxygen,_

Tsn = 167ORp:mia/sec_ /_ • ¢_T = 199°R

P,n ==84.3 P = 90.8 psla

r_ 2.84 OuaJity- 0.12

Stage 2

HydrogenExit

Tin= 280OR

H),drogefl Pin= 46.2 psla

T =, 547°R _n= 0.182 Ibm/see

P = 46.6 psla Stage 3

Oxygen Exit

Tout = 198°R

Pout = 78.3 psia

Quality = 0.95

FD 278950

Figure 65. RLIO-IIB Oxidizer Heat Exchanqer -- Pumped Idle Performance (Reversed

Hydrogen Flow)

6O

k
Pratt & Whitney

FR-18046-3
Pratt & Whitney

FR-18046-3

62

IM49;1(' _

• ,a. w Wh,..ey

FR-18046-3

Ott_;IC
Pratt & Whitney

FR-18046-3

65

,.,,. @t

I
: Pratt & Whitney

', FR- 18046-3

i

SECTION IV

HEAT EXCHANGERANALYSISAND DESIGN

The OxidizeHzeatExchanger(OHE) heattransferanalysesthatprovidethd ebasicOHE

designrequirementsandthoseforsubsequentdesigniterations werebasedon limitingtheheat

inputtotheliquidoxygenduringbothTHI andPIoperationuntila 5% to10% oxidizequrality

(percentvaporbyweight)isachieved.Increasehdeattransferratecsouldthenbeappliewdithout

causingunstablboiling. e Theserequirementhsadbeenestablished duringthetestsandstudies

leadingtotheSpa_ Tug EngineReport(P&W ReportNo.FR-7498,21 Muy 1976),and the

OrbitTransfeVrehiclAdv e ancedExpanderCycleEnginePointDesignStudy(P&W ReportNo.

FR-14615,15March 198D.The maximum allowablheeatfluxvaluesfortheliquiodx)genat

THI andPIconditio....verecalculatacc ed ordingly.

The basicRL10-11BOHE designfluidconditionares showninTable4.The same inlet

flowrates, temperaturaesndpressuresweremaintainefdorallOHE designanalysesThe. initial

heattransfearnalysmdefineadthree-stacgroess-flhoeaw texchangerFigur . e71showstheinitial

three-stahgeae texchangerarrangementwiththe10% Pumped Idledesignpointperformance

: parameters; theTHI andFT off-design __rformanceparame_rsarealsogiven.

Table 4. RLIO-IIB Engine Heat Exchanger Design

Fluid Conditions

10% Thrust

P.teatExchanger 10% Quality

Ox_/_en Inlet Point

Flowrate -- Ibrn/sec 2.84 2.84

Pressure -- p_i_ 84.3 --

Temperature-- °R 167.3 --

Enthalpy -- B_.u/lbm 63.2 84.9

Hydrogen

Flowrate -- lbm/sec 0.182 0.182

Pressure-- psia 47.1 --

f 1omperature- 'R 6_9.0 --

Enthalpy -- Ptu/lbm 2161.0 1822.0 I

The initiOHE al wasdesignedtosupplyslightly-superhoeate xygednat209°Rand77.2psia i

at the exit. Stages 1 and 2 are of etched or milled-channel stainless steel (Thermal Skin®) !

constru'tion with metal felt insulation between the plates. Stage 3 is of stainless steel Thermal i

Ski.-,.construction with no insulation between the plates. Detailed geometry and performance '

informatmn for the individual stages can be found MFigures 72 through 74. I

Stage 1 was demgned to assure stable boiling of the liquid oxygen at the conditions

experienced duri"g THI operation. The metal felt insulation density and thickness were selected

to keep the heat flux to the oxygen below the maximum allowable heat flux for stable boiling

(0.95 Btu/ft '_sec) at THI. The calculated conductivity of the compressed metal felt insulation

used in the analysis was 0.041Btu-ft/ft2-hr-°F.

PIC.:.:CZDI)_GPAGI_ BLANK NOT FILMED

"" 67

PA -.INt m NAU.V

• ®
Pratt & Whitnel,

_" FR-i8046-3

.,

Hydrogen Exit

Tout = 238OR

Pout= 46.4 psla

2 /1 Oxygen

Oxygen Inlet

Tin = 167.3TM

Pin = 84.3 psla / I T = 199°R

In= 2.84 Ib/sec P = 82.1 psla

Stage 2

Hydrogen hllet

w Tin = 639°R

Hydrogen Pin= 47.1 psla

T = 324°R rn= 0.182 Ibm/sec

P = 46.8 psla

Oxygen Exit

Tout = 209° R

Pout= 77.2 psia

Heat Exchanger Performance at Off-Design Conditions

Tank Head Idle Mode Full Thrust Level

Oxyg6n Tin" °R 166.0 167.0

rout- OR 539.0 263.G

_ P,n- psia 20.0 538.8

Pout- psia 17.3 534.0

AP - psid 2.67 4.8

Exit Quality 1.0 0.1

Hydrogen T,n- °R 559.0 431.5

Tout" OR 404.9 214.1

P,n psi_" 8.6 692.0

Pout" psia 7.25 692.0

Ap - psid 1.35 0.0

FD 278946

Figure 71. RLIO-IIB Eugine --Gaseou._ Oxygen Heat Exchanger Geometry (At Pumped

Idle Design Point)

,t:

, 68
Pratt & Whitney

FR-18046-3

Dimensions of

Core

, Thermal Skin

!

i }.125 Geometry Blow-Up

02 in.._lP-- H2 Plate-_,

!1 ., co.o,o

J H2ln" (Tu;_I_ 90°)--__2JI _ _J,.

1 o,o

l

1

Geom.etry __ H2 Plate 02 Plate

No. Plates 12.0 11.0

Passage Diameter, in. 0.0513 0.0336

Flow Area, in.2 1.213 1.602

Heat Transfer Area, ft2 5.2

Core Weight, Ib 7.5

Insulation Type 2% Dense Metal Felt (0.150 inches compressed to 0.084 Inches)

Insulat!on Material' 300 Serle._ Stainless Steel

Heat Exchanger Performance

Design Point Off Design .

: Tank Head Idle Pumped Idle Full Thrust

|

in(H2), - Ibm/sec 0.0106 0.0182 0.006

r_(O2),- ':_m/sec 0.339 2.84 1.00

T,n (H2) - °R 538.0 324.0 261.0

1 T,, (02) - °R 166.0 167.0 167.0 !

f T°ut(H2) " °R 476.0 310.0 236.0

' To= (02) - °R 168.0 168.0 168.0

&P (H2) - psi 0.5 0.1 _,0.0

&P (02) - psi 0.354 0.7 0.09

02 Exit Quality 0.1 0.0 0.0

Q - Btu/sec 2.4 1.0 0.55

Q/A, Average - Btu/ft 2. sec 0.56 0.19 0.102

FD 278941

.I

l Figure 72. RLIO-IJB Engine -- Gaseou._ Orvgen Heat Exchanger (S:age I Core)

1

i! 69
: Pratt & Whitney

FR-18046-3 i

, Dlmeflslons of Core _ 14.0

02 in Thermal Skin 3.12

Geometry Blow-Up

J H2 In. 0.015

All Dlmenldons Are In Inches

H=

i -().010

| B:aze 0.004 Thick |0.025

02 Plate (Turned 90°}

_.1-/

. 0.02 .. . _"0.010

Geometry

H2 Plate 02 Plate

No. Plates 20.0 19.0

.= Passage Diameter, in. 0.0513 0.0336

Flow Area, in.2 8.199 2.77

[ Heat Transfer Area, ft2 36.6

Core Weight, Ib 53.3

Insulation Type 5% Dense Metal Felt

Insulation Material Nickel 200

Heat Exr,hangar Performance

Design Point Off Design

Pumped Idle Tank Head Idle Full Thrust

m(H2), - Ibm/sac 0.1638 0.098 0.054

h1(O2), - Ibm/sac 2.84 0.339 1.00

T_, (H2) - °R 324.0 538.0 260.9

Tin (O2) - °R 168.1 168.0 168.3

Tout (H2) - °R 230.0 397.0 211.7

Tout (02) - e':l 199.0 449.0 195.5

&P (H2) - psi 0.10 0.53 .-0.0

,_P (02) - psi 1.50 1.72 0.08

02 Exit Quality 0.1 1.0 0.0

Q - Btu/sec 60.5 65.34 10.89

Q/A, Average - Btu/_.sec 1.653 1.785 0.297

,: FD 278948

"_'i Figure 73. RLIO-IIB Engine -- Gaseous Oxygen Heat Exchanger (Stage 2 Core)

70
; Pratt & Whitney

._. FR-18046-3

I

t

Dimensions of Core

f

. ,_I.-4.0-_ / 02 In

5.0

•_, Thermal Skin

:, "i I H2 in GeometryBlow-Up

6.065 0.015

H,Plate 2__

All DimensionsAre In Inches (Turned o, pIet90e°) L-__--_ U

. .___I__1 o.01

G(ometry

. H2 Plate 02 Plate

No. Plates 87.0 86.0 I

Passage Diameter, In. 0.0336 0.0336

Flow Area, In.2 6.475 5.180

Heat TransferArea, f12 21.3

Core Weight, Ib 19.3

Heat ExchangerPerformance

- Design Point Off Design

Pumped Idle Tank Head Idle Full Thrust

in(H2), -Ibm/sac 0.182 0.109 0.06

fn(O2),- Ibm/sec 2.840 0,339 1.000

Tin(H2)" °R 639.P 559.0 431.5

Tj. (02) - °R 19_ 449.0 195.5

Tou(H2) t " °R 324.0 538.0 260.9

,, T_ (02) " °R 209.0 539,0 263.2

_ 't AP (H2)- psi 0.30 0.82 0.0

; Ap (Of) - psi 4.28 0.30 0,02

! 02 Exit Quality 1.0 1.0 0.1

Q - Btu/sec 213.0 14.197 40,2

Q/A, Avnrage - Btu/ft2.sec 10.0 0.666 1.887

' FD 278949

•: Figure 74. RLIO.IIB Engine -- Gaseous Oxygen Heat Exchanger (Stage 3 Core)

I

" 71

-

II_NNK' ®
,_ Pratt & Whitney

FR-18046-3

" Stage 2 was designed so that no u_table boiling of the liquid would occur at pumped idle

flow conditions. It required 40% dense metal fiber insulation between the hydrogen and oxygen

plates. This insulation is too stiff to conform to the plate surface and therefore must be brazed to

the plates. The calculated equivalent conductivity of the 0.025 inch thick insulation and braze is

0.294 Btu-ft/ft2-hr-°F. The maximum allowable heat flux for stable boiling at PI is 2.62 Btu/ft 2

sec. The calculated maximum heat flux for this configuration is 2.41 Btu/ft 2 sec at PI.

Stage3 ofthe OHE was designedto deliver209°R superheatedoxygenat h,ePI design

point.The oxygenthatflowsthroughstage3 isalwaysabove5% qualitysono insulationisused.

The averageheatfluxatpumped idleis10.0Btu/ft2sec.

The pressuredropcalculationfsortheRL10-1IB OHE arealsobasedon work done inthe

P&W Space Tug Engine Study (P&W Report No. FR-7498).The hydrogenflowisallsinglephaseand thepressuredrop calculationwers estraightforwarThd.e oxygenflowisa combination

- ofsingle-phaseflowand two-phaseflowatthePI designpoint.Oxygen single-phaseflowoccurs

instage1,thefirsthalfofstage2,and theend ofstage3.Two-phase oxygenflowoccursinthe

lasthalfofstage2 and most ofstage3.Two methodswere usedtocalculatthe etwo-phaseflow

..

pressuredrops.The homogeneous model is most accurateat low vapor qualitieand s the

: _ separated flow model, with the Martinelli-Lockhart correlation, is more accurate at higher

qualities (and also gives higher pressure losses). The total oxygen pressure drops at PI using the

homogeneous and separated-flow models are 4.4 paid and 7.1 psi& respectively. Since the

MartineUi-Lockhart separated flow model is the more conservative method, it was used for

calculation of all two-phase oxygen pressure drops.

.- The initiadlesignoftheOHE, basedon theaboveanalyses,was a silver-brazTyp ed e 347

stainlessteelcoresand end closuresTh. e calculatedweightofthedesignwas 130pounds (Ref.

LayoutDrawing No. L-238388,Sheets1-3).Thisweightwas unacceptabltoe NASA, even fora

demonstrationunit.An engineeringreviewofthe designindicatethd atitcouldbe changedto

6061T-6aluminum with minor designmodifications.The calculatedweightofthe aluminum

OHE was 51 pounds,but therewas reluctanceto make thechange becauseofthepotentially

more difficultfabrication(verylimitedP&W experiencewithaluminum weldingand brazing).

However, afterweighingthe known risksand benefitsthe decisionwas made to go with

aluminum and theredesignwas accomplished(Ref.LayoutDrawing No. L-238388,Sheets5-7).

Pred,ctehdeattransfeprerformancewas essentially thesame asforthestainlesssteeldesign,but

thesecondstageinsulationhad tobe changedtocompressednickelfelti_obtaintherequired

heattransfecroefficiewintthmetal-to-metaclontactinsteadofbrazedsurfaces.

Concernswithproducibiliotyfdesigntolerancefsorphoto-etchefld owpassagedimensions,

insulationconductivitiefls,uxles._ vacuum brazedconstruction,and theheet transferanalysis

resultedin unplanned designsupport effortsto determinetheirvaliditiesAs. a result,

' modifications to the flow passage groove dimensions and shapes were found necessary through

" sample panel etchings to assure producibility for the required flow areas. Flow passage geometry

was revised accordingly.

Also, conductivity data could not be found on metal felts used to limit heat transfer at the

OHE Stages 1 and 2 operating conditions. Contacts witL various testing laboratories resulted in

the selection of Dynateeh, Inc., Cambridge, Mass. to perform conductivity testing. A decision had

I been made earlyintheOHE designefforttoprovideaccesstotheinsulationrpacesforvel_ting

during brazing,and allow the use of vacuum or pressurizedgases to tailorinsulation

conductivities if necessary. Accordingly, the conductivity tests of stainless steel and nickel felts

: by Dynatechcoveredvacuum,Nitrogenand Helium atmospheresatOHE designthicknessesA.

schematic of the test setup is shown in Figure 75. The results are given in Table 5. They showed

- # that the effective conductivities in the planned Nitrogen atmosphere was far below the values
Pratt & Whitney

FR-18046-3

predicteduringthedesignam _es,butby varyingtheatmosphereacceptablres e ultcsouldbe

produced(Ref.DynatechReportNo. PRA-105,October1983).

Initiaclontactswith potentia!aluminum heat exchangerfabricationvendorsresultedin

designchangesto improvetheprvc.icibility of thealuminum OHE designs.Modificationtos

increassetagesI and 2 thermalskincoverpanelthicknesswere made toreducethepossibility of

brazealloysilicondiffusionthroughthe parentmaterial(potentiapol rositya)nd to provide

raisededgestoallowforweld repairofthepanel-to-headesrlotbrazejoints,ifnecessary.These

modificationhosweverincreaseboth d thesizeoftheOHE and thecalculatewdeightfrom 51 to

55pounds.The modificationare s shown on P&W LayoutDrawing No. L-238388,sheets8-10.

Sheet4 ofdrawingL-238388presentsthe OHE mount provisionfsorthebreadboardengine.

An independentheattransfearnalysiofs theinitiasltainlesssteeldesignswas conductedby

Opticsand AppliedTechnologyLaboratory(OATL),a divisionofUnitedTechnologieRese s arch

i Center (UTRC). The same propellant supply conditions, flow rates, and insulation conductivitiee

' used for the design analysis were specified. A 100 node finite element cross flow heat exchanger

computer analysis program previously developed by UTRC was modified by OATL to utilize the

OHE design configuration, propellant conditions and characteristics, and insulation conductivities. This computer code provides a more detailed analysis since it separates each stage of the

heat exchanger iuto a nodal array and computes the heat transfer and pressure drop for the

volume represented by each node based on local flow conditions. This is of particular importance

during oxygen vaporization (two phase flow) whet, the fluid properties can vary dramatically.

This analysis, as summarized in OATL Report No. 83R-280169-3, dated 24 August 1983,

predicted higher heat transfer rates than the original design analysis in the two-phase flow

regions of the OHE. Consequently, the higher heat transfer in Stage 3 at PI would cool the fuel

too much and prevent sufficient heat transfer in stage 2. As in the design analysis, the I

substitutionof aluminum for stainlessteelhad a negligibleeffecton core performance.

However,the possibility ofexcessiveconductiveheattransferinstages1 and 2 oxidizeinl r ets,

where the hydrogen panels were brazed to the oxygen headers, was recommended for additional

analysisTh. e OATL computer program was furnishedto P&W for analysisreviewand

developmentofdesignr,odifications.

¢

The designreanalysis(reporteind R.J.Peckham toJ.S.Henderson memorandum of_ I

August1983and includedinthisreportasAppen&;zC),recommended a 12% increasine Stage2

insulationconductivity, and a reductioninStage3 heattransfebyr pluggingapproximately9%

ofthepropellantflowpassagesAn. alternativsolution e thatinvolvedreversingthehydrogenflow

pathand a reducingstage2 insulationconductivityby a factorof9 withno changetostage3 was

alsoincludedinthe memorandum. Subseqte,ntnickelfeltinsulationconductivittyestsshowed

only 5% of the predicted (initial design) value in a nitrogen atmosphere, but twice the required

I reversed-flow configuration conductivity in helium. Entrance conductivity was reduced by

spacing the internal tV-2Panelsaway from the 02 headers and plugging two of the H 2 passages of

the two external panels at the edges where they are brazed to the 02 headers. The resultant

iii breadboard configuration schematic and predicted fluid conditions are shown in Figure 76 and

the stage 2 computer program results at PI are shown in Figure 77. The final design is shown on

P&W Layout Drawing No. L-238388, sheets 8 through 10.

:t

|

_1 "/3
Pratt & Whitney

FR-18046-3

(u

Q.

I

m

74
, ! Pratt & Whitney

,, FR- 18046-3

J

• Table 5. Thermal Conductivity Test Results

Hot Plate Temperatures

_ (Part a. Test Material. 2% 304 SST Fell)

T l = 370oR T 2 = 393OR T 3 = 417OR

AT x = 2410R AT 2 = 264OR AT 3 = 288OR

Nitrogen 0.01108 Btu 0.01125 Btu 0.01217 Btu

hr-ft-°R hr-ft-°R hr-ft-'R

: Helium 0.0526 Btu

• t hr-ft-°R

Vacuum 0.001175 Btu

hr-ft.°R

Other Conditions:

MaterialThickness (Uncorepmssed):0,150in.note.

MaterialThickness(Compressed):0.084 + 0.002in

: Cold PlateTemperature:129°R

i Hot Plate Temperatures

• _ (Part b. Test Material: 5% Ni Felt)

T_ = 178°R T 2 = 216°R T 3 = 252°R

AT 1 = 350R AT 2 = 73°R AT3 = 109OR

-j

[ Nitrogen 0.0148 Btu

hr_ft.OR

Helium 0.0565 Btu

hr-ft-°R

Vacuum 0.00592 Btu

hr-ft-°R

Other Conditions:

Test Materiah5% Ni Felt

MaterialThickness (Uncompressed):0.35 in.nore.

MaterialThickness(Compressed):0,020 -+ 0.002in.

Cold Pls_e Temperature: 1430R

,i

t

75

j ..............................
; Pratt & Whitney

', FR-18046-3

Mixture Ratio (O/F) = 6.0

Stage 2 Insulation Conductivity = 0.033 Btu/ft-hr°R

, Hydrogen inlet

Tout= 639°R

Pout= 47.1 psia

• /

Oxygen Inlet Stage 1 f Oxygen

T,°=167OR / /1--/" T=l_OR

Pin = 84.3 ps=a / / J / P = 90.8 psla

r_ = 2.84 Ibm/sec / ___y Quality = 0.12

tage 2

Hydrogen Exit

: i, T,n = 260°R

" _ Hydrogen P_. = 46.2 psla

_ T '-- 547°R {n_ 0.182 Ibm/see

: : P = 46.6 psla Stage 3

L .

" Oxygen Exit

: Tout = 198OR

i Pout --- 78.3 psia

Quality = 0.95

FD 278950

Figure 76. RLIO-IIB Oxidizer Heat Exchanger -- Pumped Idl_ Per/ormance (Reve, rsed

Hydrogen Flow)

t

I

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i

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76

®,

," !i

._ Pratt & Whitney

FR- 18046-3

SECTION V

; BREADBOARD CONTROLS DESIGNS

The fourbreadboardcontrolstobe .... •,o_,,fozthe low thrustdemonstrationprogram were

designedand testedduringearlieRL10 r enginevariablthru e stprograms.They aretobe usedto

, performthefunctionsofthecavitatingventurivalve(CVV) turbinebypassvalve(TBV),gaseous

oxidizervalve(GOV), and liquidoxidizerflow Jntrol.Each isa variablearea.hydraulicallyactuatedvalvecapableof beingscheduledto preprogrammed positionfor s THI, PI and leT

operation.Valvepositionfeedbackisprovidedby a positionpotentiometerTh. e breadboard

. . components are discussed in the following paragraphs.

The breadboard CVV, (TL-215351) design is shown in Figure 78. The primary construction

materials are aluminum and stainless steel. It is a high-recovery design and has a throat pressure

tap. The calibration curve, showing effective area versus pintle travel, is shown in Figure 79.

The breadboard TBV (S/N CKD-1188) shown in Figure 80 was originally designed and

, used as a !__nuidcontrol valve for RL10 throttling engine demonstrations. It is a 90 degree

:., contoured port sle_,c valve driven by a rack and pinion with a feedback potentiometer driven by

- _, the pinion through a flexible coupling. Housing materials are aluminum and drive materials are

_ stainless steels. The calibration curve showing effective area versus actuator shaft rotat;on is

! shown in Figure 81.

"- " The breadboard GOV (S/N CKD-1311) is shown in Figure 82. It is a direct-drive butterfly

': valve with vertical shaft, and shutoff via butterfly to housing interference. Again, basic housing

" constructionmaterialsare aluminum and drivematerialsare stainlesssteel.The feedback

potentiometerisdrivenby theactuatorleverwhich isattachedtoboth thebutterflshy aftand

the potentiometer.The calibrationcurveshowingeffectivflow e area versusactuatorshaft

rotationisshown inFigure83.

e

FD)280452

61584

HPH

Disk 4

FD 280452

Figure 78. RLIO Cavitating Venturi Valve (CVV)

['ItZC_DING PAGI_ BLANK NOT, FI_MED 79 _,A_._
Pratt & Whitney

:'4 FR-18046-3

-.

0.30 w I ,

[] - Tank Head Idle and Full Thrust

: /_- Pumped Idle

°_°i- i I '

•,. o.,o 1 I .... _x_

ArCWea Effective /_" (Aco) - in2

, 0.15 /

0.10

0.05 -,. -_

_, / ,,

0 0.2 0,4 0.6 0.8 1.0 1.2

: Plntle Travel- In, Open

FO280453

Figure 79. Cavitating Venturi Value (CVV); S/N B54X-012; Operating Characteristics

Flow

• I

I

i

FO 280454

Figure 80. Turbine Bypass Valve (TBV) Assembly

:i

', • o '

"b
Pratt & Whitney

FR-18046-3

2.0 I | I I I I "'

- Effective i 1.8 [] Tank Head Idle TI3V

Flow Area = 1.464 In2

1.6 /_ Pumped Idle - TBV Effective

Flow Area = 0.7 In2 J

1.4 , , I l I ,

/

/" 1.2 •

TBV

Effective Flow 1.0 A[

Area/(AcD

. in.2 0.8 f

J

0.6 i,-

0,4 _-

0.2 -_ _

i,

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

Valve Actuator Angle - Degrees from Full-Closed

FD 280455

Figure 81. Breadboard Turbine Bypass Valve (TBV) Operation; Tank Head Idle and

Pumped Idle

t

IlUIiI("

al_ ,t ,,,qf i r",, -
.i

--,1 Pratt & Whitney

FR-18046-3

' ORIGINALPAG'__;_i

' OE POORQUALi]'_

: II I

r"

I

,; !

i ,1 !

_[ ,'.-' _ ,_c io.1-o,

.!

!

FC14352

Figure 82. RLIO Gaseous Oxidizer Valve (GOV)

i 82
,i

_' Pratt & Whitney

FR- 18046-3

1.6

1Maximum .564 In2 Area /

/

0.8

VJlve EffectiveFlow

Area (A_CD)- In2

t

EffectlveArea

10 20 30 40 50 60 70 80

Valve Shaft Position- Degree from Full-Closed

FD 280457

Figure 83. Gaseous Oxidizer Valve (GOV) Operation (SIN CKD-131i)

i

: £-

i
Pratt & Whitney

FR-18046-3

A fourth breadboard valve that is not specifically a part of the Low Thrust Program, but

provides extra fleyibility for liquid oxidizer control is the oxidizer control valve (OCV), which will

be used instead of the RL10A-3-3 engine oxidizer flow control (OFC). The valve is assembled as

P&W pal_cnumber BKD 7935 and i.Qshown in the exploded view in Figure 84. It is essentially a

modified OFC that provides complete liquid oxidizer flow control from shutoff to full thrust flow.

The basic construction is consistent with that of the RL10A-3-30FC, with varts modified to

eliminate unneeded functions and to provide a contoured flow control and minimum-clearance

shutoff pintle instead of the RL10A-3-3 propellant utilization (PU) pintle. The calibration curve

showing effective flow at_a versus actuator shaft angle is presented in Figure 85.

Design modifications to the turbopump were confined to those necessary for incorporation

of the 2.1:1 ratio drive gears (fuel pump to oxidizer pump) and the single-bearing idler gear (both

of which are features that were demonstrated in earlier RL10 programs). The only turbopump

design effort in this analysis and design task was to adapt the 2.1:1 ratio gear design to the

RL10A-3-3A engine pump shafts and modify the oxidizer pump elbow housing to the shorter

shaftcenter-distancerequiredby the 2.1 gears(showr_on P&W drawingsL238361 and

SL-238056respectively).

The injectorwas modifiedtoincorporatthe etorchignitionsystem,and the120cfm Bill-ofMaterialsfuelplaterigimeshwas replacedby 240 cfm AISI 347 rigimeshtoprovidemore face

cc.l;ngflowd,lringlowthrustengineoperation.

Heat exchangermockups werebuiltand usedtomodifyexistingthrottlingengineplumbin_

and toroutenew plumbing,asnecessary,toinstalltheoxygen heatexchangersand breadboard

valveson thebasicRL10A-3-3engine.No designsorengineeringdrawingswereproducedforthe

breadboardengine.Mockup photographsat the end of the fabricationstagewere used to

documenttheconfiguration. The photographsofthebreadboard emonstratorlowthrustengine

mockup areshown inthesummary asFiguresI to4.

84

Og01C
ii

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oF POO_ _,u;;::_i,_l
,, , ,,, .._

.... _,_._.,,w_._ _- '_-_'--""_7"'_. "'-'_"_'_"_" ........._ "_"'".-_""'_: ........ _ ....................... _ -

' Pratt & Whitney

: FR-18046-3
Pratt & Whitney

FR-18046-3

,i APPENDIX A

I

APPENDIXA

i ENGINESTEADYSTATE CYCLE CALCULATIONS

',

The computercycleprogramcanbe balancedinthreeways:itcanbe balanced(I)toa

• particulvaracuum thrustand inletmixtureratk,(2)toparticuloxidiz ar erflowcontroland

turbinbyp e assvalveeffvctivareeasor, (3)toa particular chamberpressureandoxidizerflow

J control valve effective area. The first method is used to define control valve areas for use in

] ,unning the other options. Since the engine operates ;n the pumpedidle mode with fixed control

_ areas, the second option is normally used to determine the effects of inlet pressure variations

and/or changes in tank pressurization flow rates in that operating mode. The third method is

I usedto simulate engine operation at full thrust where chamber pressure is held constant by the

thrust control. This option is normally used to evaluate the effects of changing inlet conditions

and other variables onengine operation while operating at full thrust.

A schematic of the RL10-IIB engine off-design cycle computer program is shown in

Figure A-1 aridTable A-1.

,?

!

I

A-1 /,._,

0mTC
•_ Pratt & Whitney

FR-18046-3

:" APPENDIX A

'i

Common In.jr Op:,,.)n ! "}pt_'l 2 Op_on 3

IVAC GUESS RPM Gums FO! BPACDI PCI

FPIP _ Gue_s RMI ACDOCI ACDOCI

FNPSP % BypaSs Gusss PC Guess FO Guess FO Guess

OPIP Op(Io_ RMI O.uess RMI Guess

ONPSP O) Bakmce on ;:OI _ RP_ F'C Guess

AFI _ on RMI _ WPC

AO_ (2) _ on 6PACOI _ RI"_

ARN Badlm¢_ on ACDOCI _ RMI

WOTP (3) Sa_m_ on PCa -- RPM

i WFTP _ on ACDOCI _ RMI

I I -" I

1 , I '°

Cak;ulaW _ _

J WD, W_- f (WI_:. R_II. WLEAK) and

! WkF.AK

_. _ Fll_l_"l_]_-'. dl_ _. EFFFP.

'_ tn_. PC - OPOT. EFFOP f (RPM. WF. FPIP. FPIT)

i.', _u, F.U, O_T) ! .'P - t (_g' Lm;_ml_. .o., F_'r) l

,,t_ Ceee'ol V_ve i._-f

LOU - f (OPDH, Calculate ACDOCV - p

PC. W,. AOIJ) f (WFo JFIP. JFTIT. PC. tic.. RMC)

Tucl_ee Turl_ne Byp_

_C' ETAT, P/P, at C4k:uliM ABYP

CSTAR'. CFVAC' - f (FTIT. FTIP.

f (R_. PC, OPDH. Wt. HPF. HPL)

Ca - f (PC, RMC)

%. - ! (RMC) Option 1: f (Wexexss '

IvAc - f (Iwc,, DKE. i_ FVAC WI_ FVACI FT_P. FllT. C_, ,_. FVAC W_ FVAC4 New • 1

= tv_cnv,c Opek_ ,_:

|

FvAC4" f (C_AC, qcr-O, 1_' AC_3CI With ACOOCV

ATH, PC) _ _ i

Fv_ - f (Iv_c, WPC) _ PCC With PC qrw WPC Turbkle

PCC - t (Zwc,, e©" -- Option 3" _4ewRPI_ X_llepow_ WPC, CF'VAC. ATH) PCI With PC Bltllm_e

FVAC w_m FVACA

ACDOCI Wlfll ACDOCV Now

RM_

"_,

_ I

FVAGDEL, IVAGDEL * ]

f (WPC, IVAC. WLEAK. ]

I

!

FD 280460

Figure A-I. Cycle, Schematic o/the RLIO-I1B Off-Design Computer Program
, Pratt

& Whitney

{"{ FR-18046-3

APPENDIXA

TableA-1. Symbol Usage in FigureA-1. RLIO-IIB Cycle

Schematic Nomenclature (Continued)

ABYP BypassValveArea

ACDOCIInputOxidizerControl Valve Area

ACDOCVOxidizer Control Valve Effective Area

AFIFuel Injector Area

AFIJFuel Injector EffectiveArea

AOIOxidizerInjectorArea

AOIJ Oxidizer Injector Effective Area

ARN Ngzzle Area Ratio

AT TurbineArea

BPACDI Input TurbineBypassVMve Area

_.CharacteristicVelocityEfficiency

rlCFO Thrust Coefficient Efficiency

CFVAC' Ideal Thrust Coefficient

CSTAR'Ideal Characteristic Velocity

CSNozzle Boundary Layer Loss and Divergence Loss

DNIMP Dump NozzleImpulse

EFFFP Fuel PumpEfficiency

EFFOPOxidizer Pump Efficiency

ETAT Turbine Efficiency FHIJ Fuel Injector Inlet

Enthalpy

FNPSP Fuel Pump Inlet Net PositiveSuction Pressure

FOI Input Thrust

:FPDP Fuel Pump DischargePressure

FPDT Fuel Pump Discharge Temperature

FPIP Fuel PumpInlet Pressure

FPIT Fuel Pump Inlet Temperature

FPIJ FuelInjectorInletPressure

FTIJFuelInjectoIrnletTemperature

FTIP FuelTurbineInlePre t ssure

FTIT FuelTurbineInlet Temperature"_

FVAC Thrust

FVACDEL DelivereVdacuum Thrust FVAC4 PseudoThrust

HP_ FuelPumpHorsepower

HPO OxidizerPumpHorsepower

IVAC VacuumSpecific Impulse at RMC

IVAC'Ideal Impulse

IVACDEL DeliveredVacuumImpulse #I

nIO ImpulseEfficiency

JFIPJacketInletPressure

JFTITJacketInletTemperature

AKE NozzleKineticLoss

ONPSP OxidizePump r InletNet PositivSuectionPressure

OPDH OxidizerPump DischargEnth ealpy

OPDP OxidizerPump DischargPressur ee

OPDT OxidizePum rp DischargTemp e erature

OPIJOxidizer Injector Inlet Pressure

OPIPOxidizePum rp InletPressure

OPIT OxidizePump rInletTemperature

AP Main Heat ExchangerPressureLoss

PC Chamber Pressure

PCIInputChamber Pressure

P/PPressureRatio

APLOIJ OxidizeInr jectorPressureLoss

RMC Chamber MixtureRatio

RMI InletMixtureRatio

RPM FuelPump Speed

AT Main Heat Exchanger Temperature Rise

VRIsentropic Velocity Ratio

Wbypm Bypass Flowrate

A3
< Pratt & Whitney

' FR-18046-3

APPENDIX A

Table A-1. Symbol Usage in Figure A-1. RLIO-IIB Cycle

Schematic Nomenclature (Continued)

WF Inlet Fuel Flowrate

WFC Chamber Fuel Flow

WOTP Oxidizer Tank Pressurization Flowrate

WFTP Fuel Tank Pressurization Flowrate

WLEAK Coolant Flow to Gearbox and Dump Nozzle

WO Oxidizer Flowrate

WPC Chamber Propellant Flowrate

WT Turbine Flowrate

The pump operating characteristics are simulated in the programs using head coefficient/flow coefficient and efficiency/flow coefficient relationships derivedfrom RL10 pump test

data. The characteristics used in this program for the main pumps are shown in Figures A-2

through A-8.

Turbine efficier.cy characteristics were obtained from RL10 turbine rig test data and axe

'. used inthe simulation as functions of isentropic velocity ratios.

= : Main chamber and primary nozzle off-design coolant pressure loss and temperature rise

characteristics are simulated in the programs with regression equations that calculate AP and AT

characteristics as functions of fuel flow, chamber pressure, characteristic velocity efficiency,

jacket inlet pressure, chamber mixture _atio, and combustion temperature. The equations are

shown in Table A-2. They were generated by fitting test data and analytical predictions of

chamber-nozzle heat transfer characteristics. Chamber-nozzle performance is calculated in the

cycle programsby applying performance loss characteristics obtained from various Joint Army

Navy NASA AirForce(JANNAF) performanceprogramsto JANNAF One Dimensional

Equilibrium(ODE)ideaplerformacer,predictions.

0.7

0.6

J

Fuel Pump 0.5 /

Efficiency

0.4

0.3

o ?

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

Fuel Flow Coefficient

FD 280461

Figure A-2. Fuel Pump First Stage Performance Characteristics (Fuel Pump Efficiency);

RLIO-IIB Et_gine

A-4

0g07C

q,

t
,_; Pratt & Whitney _ FR-18046-3

APPENDIX A _x

'o .

b

, 0.65 -

0.60 _

Head Coefficient _ _.

0.55 _ _'

t

o._ !

0

, 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 :

Fuel Flow Coefficient !_

FO_ I

i

i

Figure A-3. Fuel Pump First Stage Performance Characteristics (Head Coefficient); RLIOliB E_ine

!

0.6 y i

j

0.5 _

Fuel Pump 0.4 /

Efficiency /

0.3 f

2

0.2

0"7'

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

Fuel Flow C_fflclent

FD 280483

Pigu , re A-4. Fut'l Pump Second Stage Performance Characteristics (Fuel Pump Ef/_ciency);

RLIO-IIB Engine

A-5
Pratt & Whitney

FR-18046-3

APPENDIX A

0.70

0.65 _'_

Head Coefficient

0.60

\

0.55

° 0

7 - 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 Fuel Flow Coefficient

FD28O484

Figure A-5. Fuel Pump Second Stage Performance Characteristics (Head Coefficient);

RLIO-IIB Engine

0.7

0.6 _.

0.5 /

OxidizerPump /

Efficiency 0.4

0.3 •

0.2

0

0 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16

Oxidizer Flow Coefficient

FD280465

Figure A-& Oxidizer Pump Performance Characteristics (Oxidizer Pump Efficiency); RLIOIIB Engine

,p

A-6
Pratt & Whitney

FR-18046-3

APPENDIX A

0.75

0.70 N

k,

-lead Coefficient _ ,

o.es - &_ i

0.60 ,,

1

0 0.0: L04 0.06 0.08 0.10 0.12 0.14

OxidizerFlow Coefficient ;_

FO;,ram i

.4

I

Figure A-7. Oxidizer Pump Performance Characteristics (Head Coefficient); "

RLIO-IIB Engine

1.1

' 1.0 _._

0.9 i,-

0.8 f

0.7 _

_/1(_at Engine /

[)eslgnPoint) 0.6 / L

_/D VFD

0.4 I I

RL10-11B 0.711 0.392

0.3

0.2

0.1

0

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

" VelocityRatlo/(VelocityRatio at EngineDimlgnPoint)

FD 2804e7

_ ! Figure A-8. Turbine Efficiency Characteristics -- RLIO-IIB Engine

I

I A-7
,j

Pratt & Whitney

_" FR-18046-3

APPENDIX A

Table A-2. Main Chamber and Primary Nozzle Heat Transfer Predictions

The following equations are used to predict the off-design main chamber and primary nozzle coolant

temperature rise and pressure loss characteristics:

KIXRPC °_'4X RPIN °°_ × RECS '_' >¢RTC 24_7

AT

RRM '''_× RWF °_

AP ffi [JFIP - (JFtP _ - (-W_)' × (-_) × PAVGD × PD X2 )0_] Xl.73

where:

AT = Coolant temoerature rise at off-design point

AP = Coolant pressure loss at off-design point -ir

t

K1 = Constant to set the design point ievel l

Chamber pressure RPC =

19.0 '

t

RPIN = Inlet Pr.ssure of Coolant _

70.0 I

i

RECS = q¢" !

0.94 }

Combustion Temperature RTC =

7147.0 i

Chamber Mixture Ratio RRM =

5.0 I

t

RWF = Coolant Flowrate !

0.298 i

JFIP = Coolant Inlet Pressure i _

1

WFCD = Coolant Flowrateat Engine L _,nt

TAVGD = Average Temperature of Coolant in Jackttat Engine Desig_ Point

PAVGD = Average Pressureof Coolant in Jacketat Enz!.neDesign Point

APD = CoolantPreesureLoss at Engine Design Point

WFC = CoolantFlowrateat Off-DesignPoint

TAVG , _ AverageTemperature of Coolant in Jacketat Off-DesibmPoint

Off-design heat transfer charazteristics for the GOX heat exchanger are simulated in the

programs using correlations established for similar heat exchanger configurations. I'hese

correlations are for a compact configuration. The equations usedare shownin Table A-3.
Prat_ & Whitney

FR-18046-3

APPENDIX A

Table A-3. Oxygen Heat Exchanger

Heat Trans[Er Predictions

The following equations are used *_ predict the off-design GOX heat exchanger heat transfer characteristics in

the off-design cycle programs:

Cmi n = Lowest of CPo X W O or CPF X W F i.

CN, = Highest ofCvoX Woor CpFX WF

UA ffi Overall Heat Transfer Coefficient x Surface Area

XNTU = UA

Cmin

! Cm i j

E.Tectiveness ffi f _ XNTU) from curve

Heat Flux ffi Effectivenc-_ × (TFIN-TOIN) X Cmia l

i

'Kays, W. _d London, A. L., Compact Heat Ezchan_rs, McGraw-Hill, New York, 1964.

'1

i

I

1

i'

I

I

'l !:

:i t

!-

p

_ A-9
,% ]k_

. Pratt & Whitney

_"" ' FR-18046-3

_, APPENDIX B

"B

APPENDIX B

DEFINITION OF ENGINE TRANSIENT CHARACTERIbTIC$

Two transient computer simulation programs were used to define the transient characteristics and control system requirements fo_ the RL10-IIB engine. On_ of these programs was used

to simulate turbopump cooldown (THI transients). The other program simulated acceleration

transients to PI and let for the engine.

Tank Head Idle simulations can be made with various pro, Alant conditions (gas, liquid or

two-phase), and various initial metal temperatures. The methods used to simulate the

components in the transien*_ simulations are similar to those used in the steady state cycle

program. Th. major differences in the programs are the dynamics included in the transient

programs and additional routipes required for THI cooldown.

1. ACCELERATION TRANSIENT SIMULATION

_-" Figure B-1 and Table B-1 present a simplified flow schematic that shows the more

important calculations and convergence loops used to simulate the RL10-IIB engine operation

: during acceleration transients. Dynamics are among the main considerations in this program. A

_ brief discussion of the dynamics used is included later in this Appendix.

.*7

;¢

B-1
_ _ _ _ 14.

Pratt & Whitney

FR-18046-3

APPENDIX B

I InltimlzJtlon _ inlet C.,onclitlonl I

I _,,__v_.__--'--!"

IC_) I Valve Areal - f (, or P) I /

F.,m° I !

FlrlI Stlge lwD

CiIcullm P2 T2 I_

qF_'l. TQFm " /

I_ qN. W,. P,. T,)/

I Fuel Pump Pump

_ Second Stlge _e Pt,.

e"J _l_ CIIcullte P_ T_ TIa qu. TQLp"

"_ ICsJcubttJon8 ]I °Exchange

°x"r

_ : I Iw'- f(Ps, T$, P4, T4) £To1111(APo _

I Used from

Main Heel

p,- I/c I (w, - ws)o't - oox v,_, I p,,. T,. Cllcullte At, W14- f(Pli TI. H, A)

AP Ts Ps " A, Pts) I I

'" I(W4, P4, T4, PC.

¥, _, TAU,) LTP"t'I(_)

I

[§) Wls - W14 - WLPT _W i

T | _o" wl,+ w,s

J

t t °-t

Turbine Turbine BYDUl ' Injector

_+_ CIIcul.,. VR We- f(P, P,

_ Pli/P I T(_- Ts A) Pill" f(X, PC Wo

t(ps Ts TI) , I TIe Hll. A)

8 }" N, W) (_ Pe" P'+ &Pl=

}L N - llJ f ('roT-TO_)_t

W.- I(Ps P. Ts A) eox Heat ExchL_or

' APF " f(P6, Te, We)

I ATo - f(We, W14, Te, T. T13, Pe

Full ShutOff j P13, dr, TAU_

; VlJve I APo" f('r13, Pta, W14)

PI- f(VVIhPl, TI, A) I , T7 " Te - ATF

_ I m

WF"F"W

'

s°-

'WFTP or i _ _ co.¥ _....,o WFc.m. /W ° _

I T10" f(Plo, We. TT, Wl, TI) I _1 Calculate TC, Rc, 7o CPC - f(7)

PlO" f(Pc, Tlo, WF, A) I Wont " f(Pc, PAMB,WF + Wo) I

Pc" 1/C J(WF+ Wo- Wo_)dt

F - f(Pc, Wc_, EFF)

I o.,_., I

FD 280468

Figure B-I. Transient Simulation Flow Schematic -- RLIO-IIB Engine

B-2
! Pratt & Whitney

, ( FR-18046-3

APPENDIX B

"_ Table B-1. Symbol Usage in Figures BI and B2

A Area -- inches 2

AS Surface Area, inches 2

C Capacitance

Cp Specific Heat Capacity -- Btu/ib m -- °R

' C, Nozzle Boundary Layer Loss and Divergence Loss

DKE Nozzle Kinetic I.<ms

dt Time Increment, seconds

EFF Efficiency Terms (Ca, DKE, _.)

FSV Thrust -- lbf

HYD Hydraulic Diameter -- inches

• H Enthalpy -- Btu/]b m

h Heat Transfer Coefficient -- Btu/hr -- ft2 -- "R

q ._.fficiency {pump or turbine)

qlv,¢ Vacuum impulse efficiency.

I_. Ideal Vacuum Specific Impulse -- sec

J Turbopump Polar Moment of Inertia -- ft-lb-zec 2

N Turbopump Speed -- RPM

P Pressure -- psia

Ap Pressure loss -- peid

"_" Pmb Ambient Pressure -- peia

Pc Combustion chamber pressure -- paia

Q Heat transferred -- Btu

R Density -- ibm/ft 3

r Mixture ratio

Rc Gas Constant -- R-lbe/'R-lbm

S Entropy - Btu/lbm-'R

T Temperature -- "R

"- t Time -- seconds

A",' Temperature rise -- "R

TAU Transient response time constant -- second

TQ Torque-ft-lbe !

J

TW Wall temperature, OR

V Velocity -- ft/sec '1

VR Turbine Velocity Ratio

W Flowrate -- Ibm/zec ".

WD Dump coolant flowrate -- Ibm/sec

WFTP Fuel tank pressurization flowrate -- ibm/sec

WLTP Oxidizer tank pressurization flowrate -- ibm/sec W F' Fuel flowrate calculated at second stage discharge -- Ibm/zec

Wo' Oxidizer flowrate calculated through oxidizer injector -- lbm/zec

X Propellant Quality

Z Component (Impeller, pump housing, etc.) mass -- Ibm

7 Specific heat ratio

Subscript Description

1, 2.... 16 Stetion locations

BP Boost pump

C Combustion chamber

D Discharge

f Fuel (propellant)

FP_ Fuel pump, 1st stage

FP 2 Fuel pump, 2nd stage

O Oxidizerpropellant

P Previousvalue

T Turbine

LI Upstream

Average

]

i

B-3

" ,
1L

J

'4,

--A

.\ Pratt & Whitney

• FR-18046-3

APPENDIX B

: 2. TANK HEAD IDLE COOt.DOWN SIMULATION

FigureB-2 and TableB-Ipresentsa flowschematicwhichshows how theRLI0-IIBengine

is simulated during a tank head idle cooldown transient. Since the effects of fluid dynamics

during the transients are insignificant compared to the effects of thermal dynamics, steady state

flow is assumed to exist at each time increment during the THI transients and a NewtonRaphson rapid convergence technique is used to balance the simulation at each increment. The

independent variables used to balance the programs are fuel flow, pressure at the inlet of the

primary nozzle heat exchanger, and chamber pressure. The dependent variables are fuel flow,

primary nozzle heat exchanger exit pressure and combustion chamber inlet and outlet flows. Fuel

flow, inlet pressure to the heat exchanger, and chamber pressure are varied at each time

increment until: (1) the assumed fuel flow at the heat exchanger inlet equals the flow calculated

through the second stage of the fuel pump, (2) the pressure calculated at the eJit of the primary

nozzle heat exchanger equals the pressure calculated at the inlet of the turbine bypass valve, and

(3) the total flOWT_teentering the combustion chamber _ the flowrate calculated at the

throat of the chamber.

C. 3. METHOIDFOR SIMULATING ENGINE DYNAMICS

Dynamic performance characteristics are determined by numerically integrating timevarying differential equations. This is accomplished by calculating the differentials from known

variables such as pressures, flowrates, speeds, etc., multiplying the differentials by the time

increment (DT) selected for the program, and adding the result to the last calculated value of the

parameter being integrated. The technique of numerical integration is shown by the following

example where flowrates through a known control volume are integrated to obtain the pressure

within the volume.

The integral equation is defined by:

• . P = fZWdt

where P is pressure

and Z W is summation of flow rates crossing volume boundaries

- _ Expressing the equation in finite difference form: [

' _ Pn = Pn-I+ AP

t where Pn is pressure at time = ,_

i and Pn-1 is pressure at time = n-1

Using numerical integration

AP = Z W • DT

': where DT = integration time increment

I B-4
Pratt & Whitney

_ FR-18046-3 i.

[

L

I..,-'_tlo.,.d ,n_tCo_d.,on|

/

. APPENDIX B

I [ Inlet Linestand Vldvel t

Condltk)ned Unoondlfloned

l I

Fuel Pump L rank Heed Idle • _ FIrM Siege _ TranSfer .__

Tank Heed idle I- EquaU°ns'l)

I'_ Transfer

Eclus_on_"and

Po" I(X,P,, WF,

. ._ T.H.A), II

Fuel Puml) Tlnk I-le_ Idle Cxmver0ln¢o LOq) on FloMIN

Second Stl_e Heat Transfer (Ctmnge Oxidlmr Pump

Tank Head Idle Ec_ I) and Diecharge Premum

Heat Transfer Pot - f(X, Pu, Wo', Unffi Wo- Wo')

Equatk)nd !) and T. H, A)

. w,' - f(x, e,. Wo= f(x.P=,.Pv.

_' PHEX. T. H. A) T.H. A)

AT - I(Pc, "n WF)

" -- To- f(l"v. _T, Tp. dr. TAU) _ and AT

_ - qR.ex. We. T,_ To) kcems GCX

Pn" I(PNa, AP) Heat Exchanger

From

Tnlmient Time LOOp WF Pu" Po When 1

Turbine _ Valve OxJdlzi'

Injector

_u-_v,._ T.,) w.::'(Pu-- Tu-;_: ,)

OOX Heat Exchanger Ii _ i

ATF- I(WF. Wo, TF, To, PF, Po)

Convwgence .onp APF- f(TF. PF, WD NOteS:

on Tem_ _To- f(W F, Wo. TF, To, PF. Po) (1) Standard Tank Head

WF Pu - f_.,'_'_, C,h, AS, T, de)

- @, 1T1_.Yo. , _,_)

Fuel InJect(_ O - f(h, "W. T, dt)

Pu" f(Pc. Tu. A. W F) V1 - f(W. _1. PI. A) V2 - f(W, H2, Pg', A)

I H, - f(O. V,, V:.. H,)

We PC S2, T2. X=.- f_P2, HZ)

"t - Wo/wF (2) NewtonRal_eOn

Wout " f(Pc, PAMO, ,_, RO "I'c, _ Wo Convergence Te(;hnk:lue:

Tc, Y)

FSV - f(Pc, Wout, ¥, IVAC' independent Dependent

_ _,_, C_, DKE) Vlnlblel Vlrlable8

WF WF, Wp

Change independent Pxex PHEx Outlet

Variables Unffi Pc Wo + Wv, Wo.t

Dependent Varlal_es

; Are BManced (2)

FD 280469

:-. ['is.,re B-2. Operationo/RLJO-IIB Engine During Tank Head Idle Transient

_," B-5
..__ 9:,._._'_ :.-' \ " •

Pratt & Whitney

FR-18046-3

APPENDIX B

This method of numerical integration is used to define the dynamic behavior of the engine.

The dynamic elements that have been simulated include:

1. Acceleration of oxidizer and fuel pumps

2. Thermal dynamics of the pump (cooldown)

3. Thermal dynamics of the primary nozzle heat exchanger and t_.: oxidizer

heat exchanger (OHE)

4. Fluid dynamics of the heat exchanger and main chamber.

The integration time increment (DT) is an input variable. The DT value normally used

provides a compromise between simulation accuracy and the amount of computer time required

to run the simulation. The DT varies depending upon the operating mode of the simulation.

A simulation of the tank head idle mode requires much more computer time than a

simulation of the turbopump acceleration to full thrust. During a cooldown, fluid dynamics are of

secondary importanct_ to thermal dynamics. This permits a large time i:,crement (1.0 second) to

"" be used for THI to minimize computer time. To accommodate the large DT and prevent

"mathematical instabilities," steady state flow is assumed during the cooldown. Dynamic heat

transfer equations are used to s-_mul_te the component cooldowns, and flowrates and pressures

are calculated as functions of the exit temperatures, pressures, and densities.

At the conclusion of cooldown when the turbopumps are started, the DT is reduced to 0.001

seconds to permit the turbopump acceleration dynamics to be considered. During accelerations to

pumped idle (PI) and to full thrust (FT) the turbopump and fluid dynamics become very

significant.

4. METHOO FOR SIMULATING ENGINE COOLDOWN

, Special calculations are required to simulate the transient thermal conditioning of the

engine. These routines were developed for the RL10 engine and checked using RL10 test data

generated under simulated space conditions at the NASA-LeRC Plum Brook station.

l For this simulation, a quasi-steady state solution of tt_ con, entional lumped mode thermal

energy transfer and storage equation is made Conduction, heat storage, phase change, free and

forced convection capability, and raaiation boundary conditions are all considered. Temperaturevariable solid and fluid properties ar_ used.

The engine lines, housings, valves, etc. are transformed into equivalent rods and cylinders.

The thermal model then performs a one-dimensional, quasi-steady-state heat transfer analysis of

the engine system. A particular component of the engine may be subdivided into several such rod

and cylinder combinations which may be linked together in different flow al,d conduction path

patterns. A simulation of a typical engine fuel pump is shown in Figure B-3.

A typicalenginecooldowncalculationisshown inthefollowingexample.In thiscase,the

enginesystemismade up ofcomponents(rodsand cylinders)atsome initiatemper l ature,and it

issubjectetod knov'nexternalheatloadsand fluidinletconditionsTh.e systemisevaluateovd er

a smalltime incrementand an energybalanceismade forthe firstrod/cylindercombination.

The changeinenergystoredinthecylinderisdeterminedby calculatingtheheatremovedfrom

the cylinder by the convective process of the coolant flow, and subtracting the heat added to the

" system from external sources. The energy change of the rod is also determined by subtracting the

B-6
1

Pratt & Whitney

' _ FR-18046-3

" APPENDIX B

heat removedby the convection process of the coolant. The energy increase of the coolant then

becomes the sum of the heat energies removed from both the rod and cylinder. This energy is

addedto the fluid in the form of enthalpy, and velocity increases arc determined by continuity

_., and energy conservation equations. The properties of the coolant leading the first component

become the inlet conditions for the next component and the calculations are repeated for each

I component in the system. The basic equations used to calctflate the thermal characteristics of the

i components duringTHI cooldown are:

i 1. Q1 ffi h,A,(Tw, -- T) dt

2. Q2 ffi h 2 A 2 (Tw2 - T) dt

3. QTOTAL= Q]. -t- Q2

_i - 4. H2 ffi H, + _QTOTAL+ (__ - _V2) X47205

t

5. plgl = P2V2

where Q = heat transferred-- Btu

A = area,ft2

h = heat transfer coefficient -- Btu/sec -- ft2- "R

' T = Temperature (Average) -- "R

dt -- delta time increment -- sec

H = fluid enthalpy -- Btu/lbm

V = fluid velocity -- ft/sec

p = fluid density -- lb/ft 3

and subscripts

1 = upstreamconditionor outercomponent(cylinder)

2 = downstreamconditionorinnercomponent(rod)

w = wallcondition

The ene,'gy removed from each component has now created a system imbalance in the form

of temperature gradients between the rods and cylinders and their adjacent components. This

imbalance initiates a conduction process which alters the distribution of the remaining energy in

the system and reduces the temperature gradients. The transfer of conduction energy is

determine_lby solution per the second law of thermodynamics. The solution obtained at the end

of one time increment provides the starting condition for the next time increment and the

analysis is continued until the temperatures of critical components (pump housings and

impellers) reach the desiredsteady state levels.

B-7

,
_:_.:,_._,:. T: ....=_..... _kT.'l,4 )

._- Pratt & Whitney

FR-18046-3 '_

k APPENDIX B

11 II

11 Ambient Heat

O Flux

/) (Free Convection + Radiation)

'_ ill i ',1 '*"

_ .--- / / ii Fluid ,_

,\ _ -

Q Between Components

(Conduction)

Axis_nmetric _,,)rmsl

" Fuel Pump Model Analog '

FD 280470 ';_

Figure B-3. Heat Transfer Model Simulates Thermal Conditions of Components and Fluids

r B-8 _q
EP"

_" i-,. t & Whitney

FR-18046-3

APPENDIX C

APPENDIX C

: PRATT & WHITNEY INTERNAL CORRESPONDENCE MEMO -- HEAT TRANSFER

ANALYSIS OF RL10-11BGOX HEAT EXCHANGER

"'.: PRATT & WHITNEYAIRCRAFT GROUP

, Government Products Division

_ ZJlTIrJl_ COitlU_PONDI_CZ

ILL10/ HEATTRANSFER

• 83-?52-11280

Tot 3° Benderson

Front R.J. I_CKHAH HXT. 2938

$ub_ects The RL10 Derivative lib GOX Heat Exchanger Has

... Been Modified Using a Hew Heat Exchanger Computer Deck

Deter AuguSt 27, 1983

" Copy Tel 3, Belch, 3,D, Doernbaoht T. KilLer, C. Llllerick,

8. Ovens

8OJOdJ_Y,

The IU,1O Derivative XXB GOX heat exchanger has been revised

aidlereviewdesign. of go6the".8. analysis The nov shoved analysis perfowas rmance done wbithelowa |

new heat exchanger couputer deck which does a more detailed

analysis. The major difference between the new analysis an_

¢%_" original analysis is due to differences between the stage 3

. blue prints (B/P), genmetry and the geometry used in the

original analysis. Once the new heat exchanger geometry was

irb.-orporated into the original model, the two analyticaltet,hniques, agreed closely. Some changes to the design of

-. the (_X heat exchanger have been made that will sake the

hea_ exchanger york properly at pumped idle. The perform-

|

ante of the modified GOX heat exchanger is included in this ,_

neno. The heat exchanger performance was generated by using

its detail.

the Othernewhheateat eexxcchhanger anger dec variati k because ons hoave f beeqreater examined to

Liprove the _)lerance to inlet conditions or to manufacturing problems.

RBHOLTSs

o Figure 1 shows the pumped idle performance of.

the Bodified RL10 Derivative lIB GOX heat

exchanger.

I

o Figure 2 shows the detailed heat f_ux and oxygen

quality information for the second stage of the

GOX heat exchanger at pumped idle.

,. o Figure 3 shows the Stage 1 geometry of the GOX

(,,. heat exchanger with its performance characteristics.
Pratt & Whitney

_" FR-18046-3

APPENDIX C

: i

,7..qenderson - 2 - August 27, 1983 : i

f O Figure 4 shows the Stage 2 geometry of the GOX

; heat exchanger with its performance character_qtics.

•i o Figure 5 sho_s the Stage 3 geometry with performance

J _ character Istlcs.

o Fig theurreesverse 6 adnd hy7drshow ogen theflowpumGped OX heat Idle excperhanforgemra.nce of

o Figures 8 and 9 show the pumped Idle performance of

the alternate GOX heat exchanger configuration.

o Figures i0 and Ii show the tank head Idle performance

for two alternate GOX heat exchanger configurations

with two Stage 3 geometry heat exchangers.

CONCLUSIONS AND RECOMMENDATIONS:

1. The modified RL10 Derivative II_ GOX heat exchanger

will satisfy the design requirements at pumped

idle.

2. The second stage of the COX heat exchanger is

sensitive to hydrogen inlet temperature. The

conductivity of the Stage 2 insulation should

be able to be modified during testing for a

hydrogen inlet temperature that is dlffeL'ent

than prediction,

3. Stages 1 and 2 insulation can be varied during

testing by changing the pressure of the gas

in contact with the Insulatlon.

4. The sensitivity of the COX heat exchanger to

hydrogen inlet temperature can be reduced by

reversing the hydrogen flow direction. The

Stage 2 insulation conductivity must be

reduced to 0.033 BTU/ft,hre°R.

5. Heat leakage from the hydrogen plates to the oxygen

plates through the headers can cause problems in

stages 1 and 2. A 0.010 inch minimum separation

must be provided between the axial flow plates and

the_eaders.

6. If fabrication problems make it impossible to make

stages i and 2, a alternate configuration which uses

two stage 3 geometry heat exchangers can be used.

This configuration can not be adjusted during testing

if actual inlet condition are not the same as predicted.

C-2
'_t_ _ _-'_'?- "_ ...... • 4

_ Pratt & Whitney

' FR-18046-3

• ! APPENDIX C

*

J. Henderson - 3 - Auoust 27, 1983

DI8CUSSION z e

The changes to the GOX heat e_changer due to fabrication

problems that affected the heat transfer model are as follows:

1. Change Stages 1 and 2 flow path covc rplates from

0.010 inches to 0.02 inches.

2. Reduced Stage 2 Insulation thickness from 0.025

lnohes to 0.020 inches.

_ These modifications to the COX heat exchanger are needed to

make sure hydrogen doesn't leak through the brazed aluminum.

Several changes have been made to the COX heat exchanger to

":+ correct heat transfer problems. Conduction of heat from the

:_! hydrogen plates to the oxygen plates through the headers

will cause oxygen boiling, instability in Stages 1 and 2. To

correct this probelm an 0.010 i_ch minimum separation will

be provided between the axial flowpath plate edges and the

headers. Two hydrogen paasdges on each side of the external

plates will also be plugged since these plates must be

brazed to the oxygen headers.

The Stage 3 B/P geometry.has a higher heat transfer convection area than called for in the original analysis. The

hydrogen and oxygen passage hydraulic diameters are also

smaller than what was used in the original analysis. The J

passage hydraulic diameter is set by what can be made during

the fabrication of the plates. These differences i; the _

Stage 3 geometry cause nora heat to be transferred from the

hydrogene lowering the hydrogen temperature to Stages 1 and ,:

2 at pumped idle. To correct this heat transfer problem,

the total heat transfer area of Stage 3 must be r_:duced.

The number of hydrogen passages per plate in Stage 3 must be

reduced from 52 to 47. The number of oxygen passages per

plate must be reduced from 42 to 37. The conductivity of

the Stage 2 insulation must be increased from 0.294

BTU/ft.hr.eR to 0.36 BTU/ftohr,eR because o£ the lower Stage

2 inlet hydrogen ten, stature at pump(d idle.

Figures 1 through 5 shoe the performance of the COX heat

exchanger with modified geometry. The modified G0X heat

? . exchanger will operate without boiling instability at pumped

idle. The exit oxygen quality o_ Stage 2 at pumped idle is

0.071. Stage 2 has a maximum heat flux at saturated conditions below qualities of 0.05 and 2.67 BTU/ft l. sac. The

maximum al_.owed heat flux is 2.8 5TU/ft ;_, sec at pump_

Idle. The performance of the modified GOX heat exchanger at

tank head Idle and full thrust has not changed much from the

original analysis.

r

• c-3
,_ Pratt & Whitney

FR-18046-3

APPENDIX C

J. Henderson - 4 - August'27, 1983 ....

The boiling stability of Stage 1 at tank head idle and Stage

2 at idle will be sensitive to insulation conductivity and

hydrogen inlet temperature. Stage 1 has the sane tolerances *

to _nsulation conduct;vity and hydrogen inlet teIperatures

as stated in the orig,nal meno. Stage 2 has an insulation

tolerance at pumped idle of from 0.28 BTU/ft.hr.sec to 0.4

aTU/ft.hr.OR with a hydrogen inlet temperature of 300°R.

The stage 2 hydrogen inlet temperature tolerance at pumped

Idle is +5 °R/-10"R with an insulation conductivity of 0.36 i

BTU/ft. hr-OR. The hydrogen inlet temperature tolerance can

be exceeded if insulation conductivity is modified to offset

the hydrogen temperatures. The conductivity of the Insu- i

latlon can be varied during testing by changing the gas in

contact with the insulation or by changing the pressure of I

the gas. Nitrogen, helium, and hydrogen can b._ used with

the insulation. The RL10 engine can tolerate _ boiling

instability pressure oscillation of +/-25t. _he hydrogen

inlet temperature tolerances on Stage 1 stability could be

increased to +40 o R/-10OR without exceedlng tk.... ,r_.__s...---,_e

:_ oscillation limits.

Some alternative GOX heat exchanger configurations that

would reduce the. sensitivities of Stage 2 to hydrogen Inlet

temperature and heat flux were examined. Reversing the

hydro_j_n flow direction through the GOX heat exhanger will

_uce the Stage 2 sensitivities. Figures 6 and 7 show the

umped Idle performance of the reversed hy6rogen flow COX

eat exchanger. The conduqtlvlty of Stage 2 must be _educed

to 0.033 BTU/ft,hr,OR. The Stage 2 exit quality and maximum

heat flux is 0.12 and 2.3 BTU/ft_.sec Stage 2 will have a

puspe_ Idle tolerance to hydrogen inlet temperature of fron

589 R to 689 R. The insulation conductivity can vary from

0.028 _TU/ft-hr. • R to 0.038 BTU/ft.hr- • R without causing

problems. Increasing hydrogen flow to the RLI0 Derivative

IIB GOX heat exchanger will also reduce the Stage 2 sensitivity at pumped Idle. To increase hydrogen flow at pumped

Idle and O/F - 6.0 would require an oxygen injector with a

1.0 in2 area, which will not be used during the low thrust

_estlng.

A GOX heat exchanger configuration that uses two Stage 3

eometry heat exchange_s has also been analyzed. The flrrt

eat exchanger is s_lit into two stages. Stage 1 uses 26 of

the 37 oxygen passages in the plate. Stage 2 uses 11 of the

37 passages. The oxygen flow areas of Stages 1 and 2 are

3.286 In a and 1.39 in _ , respectively. This GOX heat

exchanger configuration requires that a portion of the

, available hydrogen be taken from the 9ump to cool the hydro- I

gen to Stage 2. During tank head Idle, part of the hydrogen

i will need to be bypassed around the GOX heat exchanger.

Thi_ conftguratlon doesn't require insulation in Sta:_s I I

and 2.

' !

t

C-4
Pratt & Whitney

, FR-18046-3

' APPENDIX C

3_ .,_nde_'8on - 5 - August 27, 19_3

._i_ures 8 and 9 show pumped i_0" :.erfo.rmance for the alter-

', na-e GOX heat exchanger c_.._" ._" .-_on . The alternate con-

' _gutation will work at _:3_,,::,'..:L_e if a hydrogen muss flow

o_ _015 lb_/sec, c_me,_ _ - _ ,e pumps to cool the Stage 2

hydzo_e_ _nl_t temp:_at_c(: : 275°R. No hydrogen bypass

fl_ is _equi_ed at pr_r;,T,', ale. The Stage 2 oxygen exit

_ quality and maxirau_ hen _. _u; is 0.068 and 5.4 B_/ftZ. sac.

The allowsble is 5.7 B':u/Et_-sec. Figures 10 and 11 show

the tank head idle pe_fo_p, ance of two alternate GOX heat

exchanger configuration_ _bich use two Stage 3 ge_aetry heat

exchangers. The halt exchanger shown on figure 11 b_asaee

hydrogen around tn._ entir,., GOX heat exchanger. The hydrogen

bypass flow is 0.043 1bin set; The hydrogen flow from the

pump is 0.0265 lbm/sec. Stage I has an qxygen exit quality

and maximum heat flux of 0.093 and 0.46 STO/ftlt.sec, respect" tive17. The allowable heat flux is 0.50 BTO/ft .set. The

._'- configuration on Figure 12 bypasses 0.065 lbi/sec, of hydro- _

gin around Stages 1 and 2. The Stage 1 exit quality and

- maximum heat flux is 0.089 and 0.46 B'ro/ft2.sec. The allotable heat flux is 0.5 B_0/ft _ .set.

Tables 1 and 2 of the appendix show the GOX heat exchanger

,- petfomance comparison between the original and new heat

exchanger decks with B/_P geometry. The original GOX heat

exchanger model ' has been modified with B/P heat exchanger a

_eometries which are different from what was used in the _,

original analysis. The hydrogen exit temperatures calcu- "|

lat_ in the original computer model are" now based on t

enthalpy instead of specific heat. The two analytical techniques for oalculating heat exchanger performance agree

closely.

R. <i. Peckham

' Mechanical Components & Systems

Component Design Technology

T. R. Swartwout

r

"W

" C-5
. Pratt & Whitney

• FR-18046-3

" APPENDIX C

IL20 DLRZVATL_%.'E111

'- _ IITJ,T [XC]L*_-*CERGr'O._;g'i'l_

lq_t;'l_ tDI.J[PERFOI_IA,SlCE

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lint,: 4"/.t MIA

/

•_Oou-r- 7B.o :st,_

QUAI. • ;00%

C-6
I

i' Pratt & Whitney

FR-18046-3

APPENDIX C

; _1 _ _r-" BJ ]-- t,

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r'_ ._, ii: " ..... , J_ _]_ " 8

' ___c_c_

t Z '

! 0 --

t

I

c4 _ _
'_ Pratt & Whitney

FR-18046-3

APPENDIX C

FIGURE

RLtODERIVATIVElIB

GASEOUSOX'YGLNHEAT_XC.tt_CEl

$ "_ CORE
I

,_ Pratt& Whitney ' FR-18046-3 ' APPENDIX C IPICUIL£4 KLIODERZVATIVElib i Gl_lt_J$ Ok'_C_ t/FATP.XC.3_iCER
Pratt & Whitney

FR-18046-3

• APPENDIX C

FX_RZ

, "' ILLI0DERIVATIVE II_

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C-10
i • I

_iC-11

(_'i'
:L: Pratt & Whitney

FR-18046-3

APPENDIX C

C-12

,
/

_._;._.,,

J• C-13
C-14
I

C-15
_.T _ , ,:_, _

, Pratt & Whitney

FR-18046-3

APPENDIX C

i " RLIO DERIVATIVE_B ;'_,u_z :.

GOXHEAT EXCHANGER

, ALTERNATE CONFIGURATION

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C-16
_, Pratt & Whitney

- _- FR- 18046-3

APPENDIX C

Appendix

Comparison of Or|gtnal Computer

Program Htth Hex Heat ExChanger Oe¢k

°

J,

C-17
Pratt & Whitney

FR-18046-3

APPENDIX C

TABLE 1

RLIO DERIVATIVEIIB

GOX HEAT EXCHANGERPERFORMANCE

COMPARISONOF ORIGINALCOMPUTER

PROGRAWI M TH NEWHEATEXCH_;_uER

DECK (WITHPRINT GEOMETRY)

-4

PIJ_ED "IDLE TANKHEADIDL_ FULLTHRUST

OXYGEN ORIIG. e,..._ ORI___G. NEW ORI_._G. NEW

TIN (°R) 167.3 167.0 166.2 166.0 167.0 167.0

TOUT (OR) 2_.8 212.9 528.2 544.6 263.4 263.4

-! PIN (PSIA) 84.i 84.3 " 20.0 ZO.O 534.0 534.0

POUT(P$IA) 77.3 80.1 16.7 15.66 533.8 533.8

4P (PSI) 7.1 4.22_ 3.27 4..34 0.Z 0.19

•EXIT QUAL. 1.0 1.0 1.0 1.0 O.I 0.19

: HYDROGEN

, TIN (OR) 639.0 639.0 559.0 559.0 431. 431.5 t

|

TOUT (OR) 228.8 223.4 404.4 394.1 214. 200.4 i

PIN (PSIA) 47.i 47.1 8.6 8.6 692. 692.0 t

POUT(PSIA) 46.4 46.37 5.86 5.56 692. 692.0

"-_ _ (PSI) 0.7 0.63 2.74 3_Q4 0.0 0.0 ]

J

_I C-18
Pratt & Whitney

' _. FR-18046-3

APPENDIX C

.

J

_.2_

RL10DERIVATIVEIIB

60XHEATEXCHANGEPERRFOI_tANCE

"_ COMPARISOOFNORIGINALANDNEW

_', HEATEXCHANGER DECKS(WITHPRINTGEOMETRY)

PUMPEDIDLE TAIg(HEADiDLE FULLTHRUST

e

oei.__G. ,Ev oni___G. He_ onx..j_. .E._!U

Iq4_(LBH/SEC) 0.0182 0.0106 0.006

MO2 (LI_/SEC) 2.840 0.339 1.00

: TH2IN(OR) 296.7 289.0 540.0 547.8 261. 258.

:_ TOzIH(OR) 167.3 _57. 166.2 166. 167. ib7.

=.._ TH2OUT(°R) 285.6 277.3 __n,Z 4¢sl.9 236. 235.

.- TO20UT(°R) 168.1 167.7 " 168. 167.3 168. 168.

Ptl2 (PSl) 0:1 0.11" 1.09 0.96 ' 0_0 0.0

PO2 (PSI) .0.7 0.48 0.354 0.10 0.09 0.6

02 EXIT QUAL 0.0 0.0 0.07 0.075 0.0 0.0 t

'Q (8T',J/SEC) u.-Q'' 0.87 2.14 2.50 0.55 0.54 *

h

SIAGE2

flit2 (LBH/SEC) O.163_ 0.0980 0.054

Iq02 (LBH/SEC) 2.840 0.339 1.000 !

. TH2IN(°R) 296.7 289.6 540.0 547.8 260.9 " 257.6

TO2IN(oR) 168.1 167.7 168.0 167.3 168.2 168.3

TH2OUT(OR) 222.6 217.4 396.4 386.2 211.7 196.6

TO2OUT(°R) 199.3 199.8 429.9 487.1 195.5 198.4

PH2 (PSI) 0.10 0.20 1.09 1.19 0.0 0.0

PO2 (PSI) 1.50 1.44 1.72 3.59 0.08 0.1

02 EXITQUAL 0.04 0.028 1.00 1.00 0.0 0.0

Q (8TU/SEC} 47.0 44.8 48.5 57.3 10.9 12.5

:_ C-19

L
I i

i1 Pratt & Whitney

FR-18046-3

, APPENDIX C

t

i ?ABLE2 CON?INUED

I M_o[oL( TMK,EA_,oLE FULLT.,usT

t r_E3 o,,_j. "J_t" o,,_.__m, G_,____G. _

'*2:tB,1_t_) o.1_. o.1o9 o.o6

,' ,',o(2c_/sEcl 2.. o.339 1.oo

'rHzlN(°R) 639.0 639.0 559.0 559.0 431.5

431.5

TO2IN(°R) 199.3 199.8 429.9 487.1 195.5 198.4

:1_ TH2OUT(°R) 296.7 289.6 540.0 547.8 260.9 257.6

_i TO2OUT(OR) 209.B ZlZ.9 528,2 544.6 263.2 263.7

, IIH2 (PSI) 0.471 0.44 1.52 1.86 0.0 0,0

PO2 (PSI) 4.2 2.3 0.82. 0.65 0,02 0._2

0z EXIT QUAL 1.00 1.00 1.00 1.00 0.1 0.19

Q (BTU/SEC) 228.1 233.5 - 7.49 4.31 40.2 40.7

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