TFAWS Cryothermal Paper Session Boiling Channel Modeling in

TFAWS Cryothermal Paper Session Boiling Channel Modeling in Generalized Fluid System Simulation Program (GFSSP) Michael Baldwin and Dr. S. M. Ghiaasiaan, Georgia Institute of Technology Presented By Michael Baldwin Thermal & Fluids Analysis Workshop TFAWS 2020 August 18 -20, 2020 Virtual Conference

Presentation Outline Objective: Develop and implement a flow boiling model into GFSSP, with emphasis on fluids LH 2, LCH 4, and LO 2. • Part I: The current state of cryogenic flow boiling – Brief review of flow boiling – Available test data and developed correlations for cryogens • Part II: Flow boiling implementation into GFSSP – Brief overview of the GFSSP structure and capability – GFSSP predictions with example test data TFAWS 2020 – August 18 -20, 2020 2

Part I: The current state of cryogenic flow boiling LO 2 LCH 4 LH 2 [1] TFAWS 2020 – August 18 -20, 2020 3

Low heat flux regimes Dispersed Flow Boiling Dryout Subcooled and Saturated Nucleate Boiling Onset of Nucleate Boiling (ONB) Twall TFAWS 2020 – August 18 -20, 2020 4

High heat flux regimes Dispersed Flow Boiling Quality/Void fraction threshold Film Boiling Departure from Nucleate Boiling (DNB) Subcooled and Saturated Nucleate Boiling Onset of Nucleate Boiling (ONB) Twall TFAWS 2020 – August 18 -20, 2020 5

Available test data LH 2 7 useful experiments: 3 include nucleate boiling 5 include film boiling 1 includes CHF LCH 4 5 useful experiments: 5 include nucleate boiling 1 includes film boiling 1 includes CHF LO 2 1 useful experiment*: 0 include nucleate boiling 0 include film boiling 1 includes CHF *two supercritical experiments were found but not included TFAWS 2020 – August 18 -20, 2020 6

Available cryogenic boiling correlations The following correlations used cryogenic experimental data in their development: • Klimenko (1982) [2] – Nucleate boiling – 312 data points (77. 4% N 2, 20. 0% Ne, 2. 6% H 2) • Steiner and Taborek (1992) [3] – Nucleate boiling – Over 13, 000 data points [water, refrigerants, hydrocarbons, and cryogens (including CH 4, H 2, and O 2)] • Some of the experimental studies contain correlations that fit their own data TFAWS 2020 – August 18 -20, 2020 7

Part I Summary • To appropriately model flow boiling, the following general heat transfer regimes need to be considered: – Subcooled and saturated nucleate boiling – Film boiling – Dispersed flow boiling • Models for the transition between these regimes are also required: – Onset of nucleate boiling (ONB) – Departure from nucleate boiling (DNB) – Dryout • Flow boiling test data and heat transfer correlations specific to cryogens are severely lacking TFAWS 2020 – August 18 -20, 2020 8

Part II: Flow boiling implementation into GFSSP TFAWS 2020 – August 18 -20, 2020 9

Generalized Fluid System Simulation Program (GFSSP) System level CFD code developed at NASA in the early 90 s Fluid Nodes: mass and energy equations are solved for pressures and enthalpies Fluid Branches: momentum equation is solved for flowrates Fluid Boundary Nodes Fluid-to-Solid Conductors: conjugate heat transfer Solid Nodes: heat source supplied TFAWS 2020 – August 18 -20, 2020 Solid-to-Solid Conductors 10

Flow boiling model in progress START NO NO ONB? NO YES NO OSV? Liquid forced Subcooled nucleate convection boiling* EXIT *Partial boiling α > 0. 999 YES NO EXIT YES NO DNB? DNB/ Dryout YES Vapor forced convection YES Subcooled nucleate boiling Film/ Dispersed flow boiling Saturated nucleate boiling Film/ Dispersed flow boiling EXIT EXIT 11

Current GFSSP flow boiling model START Vapor forced convection Liquid forced convection Film/ Dispersed flow boiling • TFAWS 2020 – August 18 -20, 2020 12

Correlations with good agreement • TFAWS 2020 – August 18 -20, 2020 13

Preliminary Results: LCH 4 nucleate boiling • Test Data: Wang et al. (2014) [6] TFAWS 2020 – August 18 -20, 2020 14

Preliminary Results: LCH 4 nucleate boiling 12000 Steiner average difference: -23. 33% Chen average difference: -21. 93% 10000 h [W/m 2 K] 8000 Wang test data 6000 GFSSP prediction (Steiner) GFSSP prediction (Chen) GFSSP prediction (Miropolski) 4000 2000 0 0, 02 0, 04 0, 06 0, 08 0, 10 0, 12 x [-] 0, 14 0, 16 0, 18 0, 20 TFAWS 2020 – August 18 -20, 2020 15

Preliminary Results: LCH 4 nucleate boiling 20000 Steiner average difference: -9. 87% Chen average difference: -16. 73% 18000 16000 14000 h [W/m 2 K] 12000 Wang test data 10000 GFSSP prediction (Steiner) GFSSP prediction (Chen) 8000 GFSSP prediction (Miropolski) 6000 4000 2000 0 0, 00 10, 00 20, 00 30, 00 40, 00 q'' [W/m 2] 50, 00 60, 00 70, 00 TFAWS 2020 – August 18 -20, 2020 16

Preliminary Results: LCH 4 nucleate boiling 14000 12000 Steiner average difference: -24. 55% Chen average difference: -24. 27% h [W/m 2 K] 10000 8000 Wang test data GFSSP prediction (Steiner) 6000 GFSSP prediction (Chen) GFSSP prediction (Miropolski) 4000 2000 0 100, 00 120, 00 140, 00 160, 00 180, 00 200, 00 220, 00 240, 00 260, 00 280, 00 G [kg/m 2 s] TFAWS 2020 – August 18 -20, 2020 17

Preliminary Results: LCH 4 nucleate boiling 14000 Steiner average difference: -22. 32% Chen average difference: -25. 34% 12000 h [W/m 2 K] 10000 8000 Wang test data GFSSP prediction (Steiner) 6000 GFSSP prediction (Chen) GFSSP prediction (Miropolski) 4000 2000 0 2, 50 3, 00 3, 50 4, 00 4, 50 P [bar] 5, 00 5, 50 6, 00 TFAWS 2020 – August 18 -20, 2020 18

Preliminary Results: LH 2 film boiling • Test Data: Hendricks et al. (1961) [7] TFAWS 2020 – August 18 -20, 2020 19

Preliminary Results: LH 2 film boiling 6, 00 E+03 5, 00 E+03 HTC [W/(m^2 K)] 4, 00 E+03 3, 00 E+03 2, 00 E+03 1, 00 E+03 0, 00 E+00 0, 05 0, 10 0, 15 0, 20 0, 25 0, 30 z [m] GFSSP Hendricks Miropolski Groeneveld correlation TFAWS 2020 – August 18 -20, 2020 20

Conclusion and Next Steps • Conclusion – Steiner and Chen correlations are in good agreement and predict select methane test data within ~25% – Miropolski correlation is not bad for film boiling of hydrogen, but fails in the nucleate boiling regime • Next Steps – Determine best correlations for each regime for each cryogenic fluid of interest – Implement the full boiling model into GFSSP – Develop regime-specific boiling correlations (if possible) – Suggest future experiments to begin to fill cryogenic boiling data gaps TFAWS 2020 – August 18 -20, 2020 21

References [1] Nuclear Power for Everybody. 2020. Nuclear Power: Boiling-Boiling Characteristics. Retrieved from https: //www. nuclear-power. net/nuclear-engineering/heat-transfer/boilingand-condensation/flow-boiling-forced-convection-boiling/ [2] V. Klimenko, "Heat transfer intensity at forced flow boiling of cryogenic liquids in tubes, " Cryogenics, vol. 22, no. 11, pp. 569 -576, 1982. [3] D. Steiner and J. Taborek, "Flow boiling heat transfer in vertical tubes correlated by an asymptotic model, " Heat transfer engineering, vol. 13, no. 2, pp. 43 -69, 1992. [4] D. Groeneveld and C. Snoek, "A comprehensive examination of heat transfer correlations suitable for reactor safety analysis, " Multiphase Science and Technology, vol. 2, no. 1 -4, 1986. [5] J. C. Chen, "Correlation for boiling heat transfer to saturated fluids in convective flow, " Industrial & engineering chemistry process design and development, vol. 5, no. 3, pp. 322 -329, 1966. [6] S. Wang, M. Gong, G. Chen, Z. Sun, and J. Wu, "Flow boiling heat transfer characteristics of methane in a horizontal tube, " in AIP Conference Proceedings, 2014, vol. 1573, no. 1: AIP, pp. 1512 -1518. [7] R. C. Hendricks, R. Graham, Y. HAU, and R. Friedman, "Experimental heat transfer and pressure drop of liquid hydrogen flowing through a heated tube, " NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON DC, 1961. TFAWS 2020 – August 18 -20, 2020 22

Questions? TFAWS 2020 – August 18 -20, 2020 23