Compressible Navier-Stokes formulation for accelerating Poisson solver of gas-liquid two-phase fluid simulations

Onodera, Naoyuki   ; Sugihara, Kenta ; Ina, Takuya ; Idomura, Yasuhiro   

Gas-liquid two-phase flow analysis is one of the most important research topics in nuclear engineering because it is essential for safety evaluation and reactor design. However, it requires large-scale multi-scale simulations, and advanced numerical approaches are needed. To meet this challenge, we have continued to develop the Poisson solver for the multiphase flow analysis code JUPITER. In this study, we aim to improve the convergence of the pressure Poisson solver by formulating the Navier-Stokes equation without using the incompressible approximation. The convergence performance was measured on 8 GPUs for bubbly flow analysis in a circular tube. The results show that the computation time and the number of iterations are reduced by half compared to those using the incompressible approximation, which indicates the usefulness of the formulation in the present study.