Meshfree One-Fluid Modelling of Liquid-Vapor Phase Transitions
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We introduce a meshfree collocation framework to model the phase change from liquid to vapor at or above the boiling point. While typical vaporization or boiling simulations focus on the vaporization from the bulk of the fluid, here we include the possibility of vaporization from the free surface, when a moving fluid comes into contact with a superheated surface. We present a continuum, one-fluid approach in which the liquid and vapor phases are modelled with the same constitutive equations, with different material properties. The novelty here is a monolithic approach without explicit modelling of the interface between the phases, neither in a sharp nor diffuse sense. Furthermore, no interface boundary conditions or source terms are needed between the liquid and vapour phases. Instead, the phase transition is modelled only using material properties varying with temperature. Towards this end, we also present an enrichment of strong form meshfree generelized finite difference methods (GFDM) to be able to accurately capture derivatives in the presence of jumps in density, viscosity and other physical properties. The numerical results show the ability of our proposed framework to model phase changes with large jumps.
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