Pool boiling simulation with two-fluid and grid resolved wall boiling model

Abstract

The standard computational fluid dynamics (CFD) approach to nucleate boiling simulation is based on the Eulerian modelling and the subgrid wall boiling model (SWBM). The liquid and vapour phase are treated as interpenetrating media and considered mechanisms of heat transfer on the heated wall are not spatially resolved. Such an approach does not distinguish locations of bubble growth from the remaining surface of convective heat transfer. The present paper introduces the grid resolved wall boiling model (GRWBM) in the Eulerian simulation of nucleate boiling. This approach distinguishes locations of bubble growth from the remaining surface of conjugate heat transfer from the heated wall to liquid. The new approach is validated against detailed experimental data on nucleate pool boiling from the literature. GRWBM and SWBM simulation results are compared to each other. The simulation with the GRWBM predicts fairly well the wall temperature transient at the footprint of bubble growth, the mean wall superheating, the void change along the pool height and the two-phase mixture swell level. The SWBM does not predict adequately dynamics of the wall temperature transient and the void fraction distribution in the boiling pool, especially under high heat fluxes.