Performance property of preconditioned Chebyshev basis CG solver for multiphase CFD simulations

Mayumi, Akie ; Idomura, Yasuhiro   ; Ina, Takuya*; Yamada, Susumu  ; Imamura, Toshiyuki*

To improve the convergence property of the communication avoiding conjugate gradient (CA-CG) method is needed for applying it to ill conditioned problems such as the pressure Poisson equation in the multiphase CFD code JUPITER. In the CA-CG method, one can avoid more communication by increasing the number of CA steps. However, this makes the CA-CG method less robust against numerical errors. To resolve this problem, we apply the Chebyshev basis CG (CBCG) method to JUPITER.