Unstructured Level-Set Method For Saturated Liquid-Vapor Phase Change

Abstract

A novel conservative level-set method for saturated liquid-vapor phase change on unstructured meshes is introduced. Transport equations are discretized by the finite-volume method on collocated unstructured grids. Mass transfer promoted by thermal phase change is computed using the energy jump condition at the interface, as a function of the temperature gradient. The fractional-step projection method is used for solving the pressure-velocity coupling, convective terms are discretized by unstructured flux-limiter schemes, central difference scheme is used for discretization of diffusive terms. Verification and validation cases have been undertaken to prove the accuracy and robustness of the numerical methods, including simulation of the Stefan problem, and film boiling on a cylindrical surface. Excellent agreement between numerical solutions against analytical solution and empirical correlations from the literature is reported.

Unstructured Conservative Level-Set (UCLS) method for reactive mass transfer in bubble swarms at high density ratio

“…Previous verification, validation and extension of the UCLS solver include: gravity-driven bubbles [11,10,8,14,13,21], droplet collision [5], bubbly flows in vertical channels [21,14], falling droplets [22], thermocapillarity [20,23], liquid-vapor phase change [25,24], mass transfer in bubble swarms [4,14]. A comparison of the UCLS method [4,11] and unstructured VoF-LS method [26] was reported in [22].…”