Optimization of phase field variables in bubble rise analysis

Sugihara, Kenta ; Onodera, Naoyuki   ; Idomura, Yasuhiro   ; Yamashita, Susumu   

The Modified conservative Allen-Cahn (MCAC) equation, which assumes a spatial distribution for the interface modification strength by the phase field method and weights it using the local velocity distribution and velocity gradient, is proposed. MCAC was applied to bubble rise calculations for four representative shapes, and the results were found to be reasonable in comparison with those of Grace and Annaland et al. In addition, the results obtained by MCAC are equivalent or superior to those of Conservative Allen-Cahn (CAC), and thus MCAC can be considered superior in that it can use appropriate even when large velocity differences occur in a part of the computational domain. Finally, this method was applied to the analysis of a bundle system, and it was confirmed that the gas-liquid interface can be captured even for flows in complex channels.