3D numerical modeling of boiling in a microchannel by arbitrary Lagrangian–Eulerian (ALE) method

摘要

The arbitrary Lagrangian–Eulerian method (ALE) is used to model the hydrodynamics and the heat transfer of an elongated vaporized bubble in a microtube. The Navier–Stokes equations along with the energy equation are solved in ALE description as a single fluid with two subdomains and a moving mesh at the interface of the liquid and the vapor phases. The numerical framework is the commercial CFD code COMSOL multiphysics with the finite element method, which has been improved by external functions to the phase changing. In the simulations, the nucleated bubble comes in contact with superheated water and starts growing. The growth rate of the bubble in the proposed model and the thin liquid film between the elongated bubble and the channel wall are in a very good agreement with the analytical solution and the empirical correlation in the literature, respectively. The interactive effects of two elongated bubbles also are presented.