Conjugate Heat Transfer Predictions for Subcooled Boiling Flow in a Horizontal Channel Using a Volume-of-Fluid Framework

Abstract

The accuracy of computational fluid dynamic (CFD)-based heat transfer predictions have been examined of relevance to liquid cooling of IC engines at high engine loads where some nucleate boiling occurs. Predictions based on (i) the Reynolds Averaged Navier-Stokes (RANS) solution and (ii) large eddy simulation (LES) have been generated. The purpose of these simulations is to establish the role of turbulence modeling on the accuracy and efficiency of heat transfer predictions for engine-like thermal conditions where published experimental data are available. A multiphase mixture modeling approach, with a volume-of-fluid interface-capturing method, has been employed. To predict heat transfer in the boiling regime, the empirical boiling correlation of Rohsenow is used for both RANS and LES. The rate of vapor-mass generation at the wall surface is determined from the heat flux associated with the evaporation phase change. Predictions via CFD are compared with published experimental data showing that LES gives only slightly more accurate temperature predictions compared to RANS but at substantially higher computational cost.

Multiphase-Thermal Flow Simulation in a Straight Vacuum-Insulated LH2 Pipe: Fuel Gas Supply System in a LH2-Fueled Ship

“…Gu et al [18] combined various correlations using a wall boiling model based on Bartolomei and Chanturiya's experiments to describe subcooled boiling phenomena [13]. Furthermore, Langari et al [19] applied the Rohsenow boiling model in CFD simulations to replicate parts of Robinson's experiments [14], while Ha et al [20] verified subcooled boiling models under low pressure and Peclet numbers. Chung et al [12] implemented simulations of Bartolomei and Chanturiya's experiments [13], comparing the sensitivity and convergence between phase-change models and parameters of the wall boiling model.…”

“…While employing an analytical approach to Seo et al [21], this study distinguishes itself by focusing on the safety evaluation of LH 2 piping under relatively high-pressure conditions, in contrast to the CHS. The previous research by Seo et al [19] focused on multiphase thermal flow simulation in the Cargo Handling System (CHS) of an LH 2 carrier, where the system operates at 1.33 bar. In this study, we analyze the piping conditions for the Fuel Gas Supply System (FGSS) in an LH 2 -fueled ship under 5 bar conditions, thus termed relatively high-pressure conditions.…”

Numerical Modeling of Subcooled Flow Boiling and Heat Transfer Enhancement: Validation and Applicability to Fusion Reactor Target Design

“…Subcooled flow boiling or forced convection boiling is used for its ability to deliver high rates of heat transfer in compact spaces and with limited wall superheat [18][19][20]. In ITER, however, highly subcooled boiling is utilised, where the fluid core is expected to remain 100°C below saturation temperature [21].…”

“…Recently, a common approach to tackling multiphase flows and flow boiling is the use of the Eulerian-Eulerian twofluid model which has seen successes in predicting void fraction, temperature, velocity profiles and chemical reactions [19,26,27].…”

“…Colombo and Fairweather in their analysis of the current models found that there were still improvements to be made in relation to modelling of bubble departure diameter, bubble coalescence and the near-wall turbulence modelling. Elsewhere, Langari et al [19], Yun et al [40] and Končar and Tiselj [41] demonstrated that the selection of turbulence model and near wall velocity profile can substantially affect the wall temperatures in boiling flows. It is clear that the two-fluid model is capable of accurate modelling of boiling flows in simple circular cross-section tubes under high and uniform heat fluxes and merits investigation of applicability to divertor design.…”