Numerical Simulations of Heterogeneous Nucleate Boiling from a Single Site

In this paper we analyze the growth and detachment of well-separated bubbles from a single nucleation site. This approach is the basic step in the simulation of nucleate-boiling and can be considered as the starting point in the study of complex heat flux mechanisms such as the Departure from Nucleate Boiling (DNB). Most of the published work in this area are empirical correlations based on experimental data and physical models which rely on simplified balances among the different forces acting on the bubble. Different numerical approaches, which are based on the Lattice Boltzmann Method (LBM) and finite-difference discretization of the macroscopic conservation equations, have been proposed more recently in the literature. However, most of the published papers consider a two-dimensional geometry. In this work we present three-dimensional simulations of the nucleate boiling process performed with the code Trio_U. We follow in time the growth of the bubble up to its departure and measure its diameter and the frequency of the process. In particular we analyze the dependence of the departure diameter from a number of physical quantities which appear in several correlations, such as gravity, surface tension and contact angle. The preliminary results we have obtained are in agreement with the experimental correlations and the two-dimensional LBM numerical results.