ML12145A438

Licensee Handout on Calibration and Benchmarking of Single and Two-Phase Jet Cfd Models

ML12145A438
Person / Time
Site:	South Texas
Issue date:	05/18/2012
From:	Ballew D, Gurecky W, Schnieder E W University of Texas at Austin
To:	Singal B K Plant Licensing Branch IV
Singal B K
Shared Package
ML12145A232	List: ML12145A312 ML12145A438 ML12145A466
References
TAC ME7735, TAC ME7736
Download: ML12145A438 (40)

Text

Erich Schnieder, Davis Ballew, William Gurecky 5/18/2012

Table of Contents Introduction .................................................................................................................................................. 4

Background:

Jet Phenomena and Terminology ........................................................................................ 4 Critical Flow ........................................................................................................................................... 6 Compressible Effects ............................................................................................................................. 7 Modeling ....................................................................................................................................................... 9 Mesh ..................................................................................................................................................... 9 Solver .................................................................................................................................................... 9 Turbulence .......................................................................................................................................... 10 Single Phase Modeling ............................................................................................................................ 10 Boundary Conditions ........................................................................................................................... 11 Single Phase Solution Methods and Controls ..................................................................................... 11 Two Phase Modeling ............................................................................................................................... 11 Mixture Model .................................................................................................................................... 11 Critical Mass Flux ................................................................................................................................ 12 Benchmark Results ...................................................................................................................................... 14 Single Phase Benchmarks........................................................................................................................ 14 Mesh ................................................................................................................................................... 14 Results ................................................................................................................................................. 15 Sensitivity to Turbulent Intensity Rate .............................................. Error! Bookmark not defined.23 Sources of Error ................................................................................. Error! Bookmark not defined.23 Future Single Phase Scope .................................................................................................................. 24 References .......................................................................................................................................... 24 Multiphase Benchmarks ......................................................................................................................... 24 ANSI / Kastner Benchmark .................................................................................................................. 25 NPARC Benchmark .............................................................................................................................. 31 NED13 (C.F. Forrest) Benchmark ........................................................................................................ 32 Discussion ............................................................................................................................................ 34 Computation Time ............................................................................. Error! Bookmark not defined.34 Critical Flow Model Benchmark and discussion .................................................................................. 35 References for Multiphase Section ..................................................................................................... 37 Conclusion and Future Scope...................................................................................................................... 39 Introduction

Background:

Jet Phenomena and Terminology FiFigureigure 1. Key ANSI terminology e 2. Multiphase free jet illustration.

Table 1. Frequently referenced terms. Symbol Unit Description Critical Flow FluxCompressible Effects Figure 3 Expected flow geometry for underexpanded supersonic flow. Taken from Ref [4].

Modeling Mesh Figure 4. Meshing adaptation example. The blue regions indicate areas where the density of the mesh will be reduced. The Red regions indicate areas of step pressure gradients where the mesh density will be increased. Solver Turbulence Single Phase Modeling Boundary Conditions Single Phase Solution Methods and Controls Two Phase Modeling Mixture Model Error! Reference source not found.has units of [kg/s/m^3] is volume liquid phase fraction is liquid density is a tunable relaxation constant Critical Mass Flux upstream Error! Reference source not found.

Benchmark Results Single Phase Benchmarks Table 2Table 2. Single Phase Benchmarks Benchmark Case Inlet Gauge Total Pressure Inlet Total Temperature Benchmarks Available * *

• * * *

• Mesh Table 3Table 3. Mesh Parameters. Figure 5 Mesh used in modeling single phase jet.Results shown in Figure Figure 6. Comparison of current static pr6 showressure field (top) for water vapor with inlet conditions PT=949K with [2] (bottom). P=4.39MPa; Figure 7. Comparison of current total prressure field (top) for water vapor with inlet conditions P=T=949K with [2] (bottom).

=4.39 MPa; Figure 8. Comparison of current total presssure field (top) for air with inlet conditions P=4.26 MPa; T[2] (bottom). T=894K with Figure 9. Comparison of current centerline static pressure plot with those of CDI [1] and Zerkle [2].

-0.100.1 0.20.30.4 0.5 0.6 0.7024681012p/p0x/DZerkleCDICurrent Figure 10. Comparison of current centerline total pressure plot with those of CDI [1] and Zerkle [2]. 0100200 300 400 500 600 70005101520Psiax/DZerkleCDICurrent Figure 11. Comparison of radial total pressure plot at 0.6 L/D away from the inlet with [3] Figure 12. Comparison of radial total pressure plot at 3.3 L/D away from the inlet with [3] 00.1 0.2 0.3 0.4 0.5 0.6 0.7 0.80123456P/P0Distance from Axis (r/D)0.6 L/D From InletCurrentFrom [3]00.050.10.150.20.250123456P/P0Distance from Inlet (L/D)3.3 L/D From InletCurrentFrom [3]

Figure 13. Comparison of radial total pressure plot at 4.3 L/D away from the inlet with [3] Figure 14. Comparison of radial total pressure plot at 13 L/D away from the inlet with [3]

00.050.10.150.20.250123456P/P0Distance from Inlet (L/D)4.3 L/D From InletCurrentFrom [3]00.01 0.020.030.040.050.06 0.070.080.090.10123456P/P0Distance from Inlet (L/D)13 L/D From InletCurrentFrom [3]

Figure 15. Effect of Turbulent Intensity Rate on Total Pressure along Centerline 0.0E+001.0E+06 2.0E+06 3.0E+06 4.0E+065.0E+0601234567Total Pressure (Mpa)Distance From Inlet (m)2% Intensity5% Intensity10% Intensity25% Intensity50% Intensity Error! Reference source not found.Future Single Phase Scope References Shock diamonds and mach disksMultiphase Benchmarks Table 4. Benchmark overview. Study Type Upstream Stagnation Pressure [MPa] Subcool [C]Benchmarks Available

ANSI / Kastner Benchmark Table 5. Boundary Conditions. Po [MPa] To [K] Critical Mass flux [Kg/(m^2*s)] Kastner ANSI Fluent Type Initial Cells Average Orthogonal Quality Figure 16. Centerline sta Space Time Multiphase Turbulence Solver Matrix Conditioner Multigrid Settings Table 6. Solver Settings. Table 7. Mesh Parameters. agnation pressure comparison. Reproduced from [2]. Setting Detailed Settingg FiguFiguure 17. Centerline static pressure. ure 18. Centerline Steam Quality.

Figure Figure 20.19. ANSI steam quality contour. [2] . ANSI stagnation pressure contour. [2]

Figure 21. The local sound speed in the coFigure 22. The local Mach number of extraordinarily high velocities surroundinindicatiompressible vapor phase. As the density of the jet falls thof sound decreases. the mixture. Rapid expansion near the break plane contrng the jet core. The Mach number at the break plane is veing our choked flow condition is met. he local speed ributes to ry near unity, Figure 23. Phase change mass transfer ratFigure 24. Turbulent kinetic energy [m^te. The largest mass transfer rates can be seen near the inthe pipe break. ^2/s^2]. The jet dissipates energy as it mixes with the envlarge L/Ds. nner radius of vironment at Figure 25. Static prF NPARC Benchmark ressure field exhibiting shock diamond pattern. Figure 26. Total pressure field.

Figure 27. StagnatNED13 (C.F. Forrest) Benchmark Table 8 : Boundary CoPo [MPa] SubExperiment Fluent tion pressure centerline plot from reference [9]. onditions for C.F. Forrest experimental benchmark. bcool [K] T @ break [K] Critical Mass flu[Kg/(m^2*s)] ux Space Time Multiphase Turbulence Solver Matrix Conditioner Multigrid Settings TType Initial Cells Average Orthogonal Quality Figure 28. ExperimentTable 9. Solver settings. Setting Detailed Settable 10. Meshing Information. tal centerline static pressure. Reproduced from [3]. ting Discussion Figure 29. Fluent multiphase r Critical Flow Model Benchmark andrun near completion. Total run time: approximately 1 weed discussion ek.

Figure 30. Initially subcooled critical fl

Error! Referenlow. Reproduced from [7]. A pressure ratio of 1 indicatesconditions. nce source not found.s saturated Figure 31. InitiallReferences DesalinaAppendix INuclear Engineering and Design Science and Engineering,AIChE ly saturated critical flow. Reproduced from [5].ationNuclear Engineering andThermodynamics an Integrated Learning Nuclear d DesignSystem Continuum Dynamics Inc Conclusion and Future Scope