A three-dimensional adaptive mesh refinement multiphase flow solver for simulating non-isothermal gas-liquid-solid flows with phase change*

We present a numerical framework for simulating non-isothermal gas-liquid-solid flows with phase change. Such flows are commonly found in engineering processes like welding, casting, and metal additive manufacturing. These processes involve fluid flow, heat transfer, solidification/melting, and fluid-structure interaction. Material properties vary vastly in these processes due to the presence of distinct phases in the domain. Moreover, the phases can evolve over time into other phases. As a result, numerical simulations of these engineering processes are quite challenging. We present a robust, scalable, and efficient three-dimensional computational framework with adaptive mesh refinement (AMR) for modeling non-isothermal and high-density contrasting gas-liquid-solid flows. The framework combines the level set method with the enthalpy method to track the three phases in the domain. A new low Mach equation is derived to capture volume changes due to phase change. The proposed method discretely conserves momentum, momentum, and energy. We demonstrate the practical utility of the framework by simulating engineering problems like modeling pipe defects during metal casting or porosity defects during metal solidification.