Study on bubble dynamics in sodium using three-dimensional MPS method

Sodium-cooled fast reactor (SFR) is one of the most promising Generation IV reactors. Design and safety eval-uation of a SFR requires sufficient knowledge about gas bubble behavior in sodium pool. It is challenging to perform numerical study on bubble dynamics in sodium pool due to the discontinuity caused by the differences of physical properties. In this study, a three-dimensional (3D) Moving Particle Semi-implicit (MPS) method is presented featuring high-order accurate scheme and Riemann-based stable multiphase model. Numerical discontinuity caused by large density, large viscosity ratio and surface tension can be handled by the proposed method. To verify the proposed method, two cases from the bubble diagram of Grace (1973) is simulated and rising velocities and shapes of rising gas bubbles are compared, both are agreeing very well. Then co-axial coalescence of gas bubbles are calculated and compared with existing experimental and numerical results. Finally bubble rising behavior in sodium is analyzed using the developed 3D MPS method.