Development of exascale CFD simulation technologies

Idomura, Yasuhiro

no journal, , 

The multi-phase multi-component thermal hydraulics code JUPITER, the urban wind analysis code CityLBM, and the in-situ visualization software In-Situ PBVR were ported and optimized on Fugaku, and their performances were evaluated. The performance of JUPITER, which is implemented in C, was compared against Oakforest-PACS, and a reasonable speedup due to the improved hardware was confirmed. In addition, the performance was further improved by using FP16 SIMD operations on A64FX. On the other hand, Fujitsu C compiler had many optimization issues on CityLBM, which is implemented in C++, and its performance was two orders of magnitudes slower than Tsubame, when the same number of computing nodes are used. Finally, we constructed an in-situ visualization environment on Fugaku using In-Situ PBVR, which was released as an open source software.