In situ visualization for high-fidelity CFD—Case studies

The growing availability of large scale computing power and facilities has caused a potential for increased accuracy in CFD simulations, allowing scientists and engineers to look beyond traditional Reynolds-Averaged Navier–Stokes (RANS approaches) in favor of high-fidelity simulations, characterized by high resolution in space and time, for industrially relevant flow configurations. In situ analysis and visualization is a promising solution in the exascale supercomputing era to reduce the size of data stored on disk and time spent for post-processing by using all available resources. This paper quantifies the impact of a tightly-coupled in situ approach based on ParaView Catalyst on three different codes, namely OpenFOAM, STREAmS, and MIGALE, which implement different numerical schemes and operate in different contexts (research field rather than industrial field). We show that the overhead is not negligible, it can be of the same order as the solution of the Navier–Stokes equations depending on the type of simulation, but in any case it does not prevent to solve the physical challenge under investigation.