Continuum-scale simulations of phase change processes are essential for assisting the design of engineering systems, such as heat pipes and combustion chambers. To quantitatively predict the rate of the phase change in micro-scale systems it is imperative to properly account for the boundary conditions at the interface between phases. For example, in liquid-vapor phase change simulations, the typical continuum assumptions are, a) temperature is continuous at the interface, and b) vapor density near the interface is equal to the saturated density. Results of molecular dynamics (MD) simulations have indicated that in many situations such assumptions are not satisfied. To address these issues, we present a framework for continuum simulations capable of relaxing the aforementioned assumptions. We use finite elements to solve the Navier-Stokes equations while correctly accounting for the flux jump conditions at the interface. Expressions for phase change rates and temperature jumps are obtained from theoretical considerations and augmented by MD simulations. Problems including the burning of solid propellants and evaporation/condensation of liquids are discussed.
5:00 PM–7:00 PM Apr 23, 2019 (US - Arizona)
PCC North, 300 Level, Exhibit Hall C-E