适用于非结构网格的气液相变准稳态VOF模型OA

Gas-liquid phase change phenomena(e.g.,evaporation and condensation)are commonly encountered in liquid rocket engines.However,existing phase change models generally rely on empirical coefficients and often require experimental calibration.To enable engineering computations of gas-liquid phase change without reliance on empirical parameters and further facilitate coupled simulations of phase-change-involved flows and combustion,a quasi-steady-state phase change model based on the VOF method and applicable to unstructured meshes is proposed.This model identifies phase interfaces based on phase volume fraction distribution,determines the direction of phase change using Clausius-Clapeyron equation,and constructs a unified-form phase change source term under the quasi-steady-state assumption,which is extended to unstructured meshes via the concept of characteristic length.The model is applied to several typical phase change processes,including the Stefan problem,film boiling,bubble condensation,Venturi tube cavitation,and droplet evaporation combustion.The results demonstrate that the model can accurately identify phase interfaces on unstructured meshes,and the computed flow field parameters agree well with theoretical and experimental data,providing a reliable phase change model for engineering simulations of phase-change-involved flows and combustion.