Simulation of Propellant Loading using GFSSPLoading using GFSSPDr. Alak Bandyopadhyay, ComputerScience DepartmentComputerScience DepartmentAlabama A & M University

July 20-24, 2009

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ESMD SPACE GRANT EDUCATION PROJECT

ObjectiveSimulation and Optimization of Propellant using GFSSPSimulation and Optimization of Propellant using GFSSPOptimal Time line for Pre-chill, Slow fill, Fast fill , Topping and ReplenishmentParametric study to evaluate Temperature, Pressure, Vent Flow Rate, Surface Temperature Modification of Existing Algorithm to reduce the Computation Time. Implementation of the work into the Senior Design Course at Alabama A & M University.p g & y

Analytical Tool: Generalized Fluid System Simulation Program (GFSSP)Model Features: Transient, Conjugate Heat Transfer and Homogeneous 2- Phase (Boiling

and Condensation)and Condensation)Boundary Conditions & Assumptions:

• Base Model is developed by NASA MSFC [1]• Miropolskii’s correlation of Boiling Heat Transfer Coefficient was used for Transfer • Miropolskii s correlation of Boiling Heat Transfer Coefficient was used for Transfer

Line Chilldown• Heat Transfer Coefficient correlation for Propellant Tanks was developed from Test

Data obtained from KSC’s Cryogenic LaboratoryPh S ti M d l h b d l d t i t i ti f li id d

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• Phase Separation Model has been developed to maintain separation of liquid and vapor in the ullage using a Homogeneous Two-Phase Model.

Propellant Loading in Launch Complex 39B

C C t Pi

LH2 Storage TankLO2 Storage Tank

Cross Country Pipe

Upper Stage Propellant TankFlare Stack

LO2 Tank

LH2 Tank

Common Bulkhead

Requirements for Propellant Loading

LH2 Loading• Slow fill – 2 lb/sec until Tank is 5% full• Fast fill 15 lb/sec until Tank is 95% full• Fast fill – 15 lb/sec until Tank is 95% full• Topping – 2 lb/sec until Tank is 100% full• Replenish – 1 lb/sec to allow replenishment due to boil-off

Pre-chill• Chilling of both tanks should start simultaneously to maintain a favorable thermal

gradient across Common Bulkheadgradient across Common Bulkhead• LH2 loading can only start after completion of LO2 loading followed by 15 minutes

of pressure test• Tank pressure must not exceed 10 psig during loading• Tank pressure must not exceed 10 psig during loading

Only LH2 Loading has been considered in this work.LO2 Modeling will be similar and not simulated in this work.g

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GFSSP Model of LH2 Tank Loading of Ares I Upper Stage

Tank Wall InsulationVent Valve

Vent Line and Flare StackCross Country Pipe

H li T k

LH2 Storage Tank

Tank

Helium Tank

Flare Stack

Ground System

Mobile Launch Pad

Mobile Launch

Common Bulkhead

LO2 TankSystem Valve

5

Storage Tank Cross Country Line

Pad SlopeLaunch Pad

Input Data for Integrated Ground System, LH2 Tank and Flare Stack Model of Propellant Loading

LH2 Storage Tank Pressure 46 3 psiaLH2 Storage Tank Pressure 46.3 psiaAmbient Temperature 85 ° FLH2 Propellant Load 48593 lb

Pre-Chill Valve C 16Pre Chill Valve Cv 16Slow Fill & Topping Valve Cv 12

Fast Fill Valve Cv 140Replenish Valve Cv 5.64

Vent Valve Area 20.94 in2

Vent Valve Cd 0.552Ground System Pipe Length and Volume 1910 ft / 879 ft3

Flare Stack Pipe Length and Volume 1305 ft /1605 ft3

Tank Volume 11,620 ft3

Ground System Pipe Mass 29314 lbT k M 8742 lbTank Mass 8742 lbFoam Mass 673 lb

Metal (Al-Li) thickness 0.1934 inFoam (BX 265) thickness (Tank Barrel) 1 in

66

Foam (BX-265) thickness (Tank Barrel) 1 inFoam (BX-265) thickness (Dome) 0.5 in

Common Bulkhead Conductance 0.045 Btu/hr-ft2-F

Liquid

Volume

Summary Result for LH2 Loading

D i P t G d S l V G d S l V Q lit Design Parameters Ground Supply Vapor Quality = 50%

Ground Supply Vapor Quality = 2%

Pre-chill Time (after start) 129 Minutes 129 Minutes

5% Tank Fill Time (after pre-chill) 23 Minutes 23 Minutes

95% Tank Fill Time (after pre-chill) 73 Minutes 73 Minutes

100% Tank Fill Time (after pre-chill) 87 Minutes 87 Minutes

Tank Chill-down Time (after start) 194 Minutes 194 Minutes

Maximum Tank Pressure (pre-chill) 15.94 psia 15.94 psia

Maximum Ullage Pressure (Replenish) 15.5 psia 14.85 psia

Maximum Vent Flowrate 0.95 lb/sec 0.67 lb/sec

Amount of GH2 Vented 4069 lb 3681 lb

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Minimum Foam Surface Temperature 6.5 F 6.2 F

Time Step Study and Effect of CPU TIME

Derived Parameters from Simulation

Base Run (Time step = 0.1 s)

Run1 (Time step = 0.05 s)

Run 2(Time step = 0.2 s)

Pre-chilled Time (min) 128 138 117

Time taken for 5% Fill(min)

23.2 22.8 23.4

Time taken for 98% Fill (min)

72.7 72.5 72.9

Time taken for 100% 86 8 86 6 87 0Time taken for 100% Fill (min)

86.8 86.6 87.0

Computational Time 11 hours 26 mins 23 hours 16 mins 6 hours 17 minsComputational Time needed for Simulation

11 hours 26 mins 23 hours 16 mins 6 hours 17 mins

Tank Inflow rate and Vent flow rate

16 WinPlot v4.60 rc1F2627 LBM/SEC Vent Valve F910 LBM/SEC Pipe 910

Inflow

12

8

Fastfill

4

Prechill

Slowfill

Topping

0 ReplenishVent Flow

9

0 2000 4000 6000 8000 10000 12000 14000-4

TIME SECONDS 9:49:43AM 03/02/2009

Pressure in LH2 Tank

P10 PSIA Node 10 P26 PSIA Node 26

18 WinPlot v4.60 rc1

P10 PSIA Node 10 P22 PSIA

P26 PSIA Node 26 P28 PSIA Node 28

17

Common Bulkhead

16Mid Barrel

End of Prechill

Ullage

d a e

15

Atmosphere

10

0 4000 8000 12000 1600014

TIME SECONDS 3:26:58PM 03/02/2009

Propellant Temperature and Quality in LH2 Tank

G G G XV10 Node 10 XV22 XV26 Node 26

Hydrogen Temperature Quality (Vapor Fraction)

200

100

0

WinPlot v4.60 rc1T10 DEG_F Node T22 DEG_F T26 DEG_F Node 2

2.0

1.5

1 0

WinPlot v4.60 rc1XV10 - Node 10 XV22 - XV26 - Node 26

Condensation Begins

-100

-200

300

1.0

0.5

0.0

Common Bulkhead Mid Barrel

Ullage

0 2000 4000 6000 8000 10000 12000 14000

-300

-400

-500

TIME SECONDS

Common Bulkhead Mid Barrel Ullage

0 2000 4000 6000 8000 10000 12000 14000

-0.5

-1.0

TIME SECONDS

Condensation Ends

TIME SECONDS 2:17:40PM 03/03/2009

TIME SECONDS 2:25:10PM 03/03/2009

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Pressure and Facility Temperature in the Ground System

60 WinPlot v4.60 rc1P1 PSIA Node 1 P8 PSIA Node 8 P9 PSIA Node 9

100 WinPlot v4.60 rc1DEG_F S Node 11 DEG_F S Node 15 DEG_F S Node 17

50

40Storage Tank

100

0

-100 Cross Country LineP d Sl40

30

Valve Upstream

-200

-300

Pad Slope

0 2000 4000 6000 8000 10000 12000 14000

20

10

TIME SECONDS 2:56:57PM 03/03/2009

Valve Downstream

0 2000 4000 6000 8000 10000 12000 14000

-400

-500

TIME SECONDS 3:02:10PM 03/03/2009

Storage Tank

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Ullage Pressure & Flowrate in Vent Line

2.0 WinPlot v4.60 rc1

LBM/SEC Vent Valve LBM/SEC Vent Valve

G ( % )

Vent Flow (50% Quality)PSID

1.5

1 0

Gauge Pressure (50% quality)LBM/SEC

1.0

0.5

0.0

-0.5Gauge Pressure (2% Quality)

V t Fl (2%Q lit )

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0 2000 4000 6000 8000 10000 12000 14000-1.0

TIME SECONDS 9:17:05AM 03/04/2009

Vent Flow (2% Quality)

CONCLUSION

The Simulation Model will be carried on at Alabama A & M University by the students in the senior design students for further optimization and parametric studystudy.The model simulates all phases of loading: Pre-chill, Slow fill, Fast fill, Topping and ReplenishA new solver technique developed at MSFC will be implemented and tested in the senior design course.The computation time is cut by 50% by optimizing the time step However further The computation time is cut by 50% by optimizing the time step. However, further study is needed to optimize further.

STUDENTS WORK• Improve computational efficiency of numerical simulation by introducing fast

solver and using fast compilerPARAMETRIC STUDY

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• PARAMETRIC STUDY• TEST WITH BROYDEN SOLVER (replacing the existing Newton Raphson).

REFERENCES and ACKNOWLEDGEMENT

REFERENCES:1. Majumdar, Aloke and LeClair Andre, “LO2 and LH2 Tank Loading and Boil-Off Analysis

Report”, report no. MPS-PR-08, NASA MSFC, March 21, 2008

Acknowledgments:Acknowledgments:

Thanks to My mentor Dr. Alok Majumdar, Ms. Melissa Van Dyke, Thermal Analysis y j , y , yBranch Chief, Dr. Andre Le’Clair, and Mr. Rick Moore, Marshall Space Center, Huntsville, Alabama.

Special Thanks to ESMD Space Grant Faculty Fellowship Program for all the support towards this work