Numerical Investigation of Nucleate Boiling Mechanisms by 2D Transient Temperature Mapping Using Lattice Boltzmann Method

Abstract

Boiling heat transfer associated with bubble growth is perhaps one of the most effecient cooling methodologies due to its large latent heat during phase change. Previous studies suggest that the major routes for heat and mass transfer contributing to bubble growth are transient conduction, evaporation of microlayer formed beneath the bubble and movement of water droplets at the vapor-liquid interface. Despite the considerable effort being made to understand the heat and mass transfer mechanisms during the bubble growth, there are several questions remaining regarding the fundamentals of bubble growth mechanisms. The goal of this research is to numerically investigate two-dimensional, space- and time- resolved, local liquid temperature distributions surrounding a growing bubble. The Lattice Boltzmann Method is implemented to simulate the nucleation of single bubble in a liquid. The MRT-LBM model is used for the hydrodynamic LBM and the thermal LBM model. A single nucleation site at the bottom wall was constructed and a small heater was placed at the central nodes of the bottom wall and rest of the bottom wall is kept adiabatic. The temperature profile at various levels of the bubble along the horizontal axis was plotted at regular time intervals.