Evaluation of preconditioned Chebyshev basis CG solver for multiphase CFD code JUPITER

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

Improvement of convergence property is an issue in applying the Communication-Avoiding CG (CA-CG) method to the Poisson solver in the JUPITER code, which analyzes a multi-phase thermal-hydraulic problem. In this work, we implemented the Chebyshev basis CG (CBCG) method and evaluated its convergence property in real problems. As a result, the CBCG method greatly improved robustness of the convergence property and succeeded in reducing collective communication to 2/3 compared with the CA-CG method.