In situ visualization of large‐scale turbulence simulations in Nek5000

Research focus area – In Situ computational steering
Application – Large-scale turbulent flow simulations

In situ visualization on high-performance computing systems allows us to analyze simulation results that would otherwise be impossible, given the size of the simulation data sets and offline post-processing execution time. We develop an in situ adaptor for Paraview Catalyst and Nek5000, a massively parallel Fortran and C code for computational fluid dynamics. We perform a strong scalability test up to 2048 cores on KTH’s Beskow Cray XC40 supercomputer and assess in situ visualization’s impact on the Nek5000 performance using a study case, a high-fidelity simulation of turbulent flow. The result of this study highlights the technical challenges posed by the integration of high-performance simulation codes and data-analysis libraries and their practical use in complex cases, even when efficient algorithms already exist for a certain application scenario.

Figure: Iso-surface of the 𝝀𝟐 criterion to identify near-wall vortical structures for the 3D turbulent flow around a NACA 4412 wing section

Reference: Atzori et al. In situ visualization of large‐scale turbulence simulations in Nek5000 with ParaView Catalyst. The Journal of Supercomputing, 2022.