Burst buffer accelerated direct numerical simulation of turbulence generated by 3D sparse multiscale grids

This study investigates the free-stream turbulence characteristics generated by a novel three-dimensional sparse multiscale grid (3DSG) using a burst buffer accelerated direct numerical simulation algorithm (BBDSA). The BBDSA achieves a fivefold reduction in computation time and an eightfold improvement in parallel efficiency by employing burst buffers to absorb large data volumes, thereby mitigating I/O bottlenecks in parallel file systems and enabling faster computation of turbulent flows. The algorithm was applied to examine turbulence modulation induced by three types of turbulence generating grids: two-dimensional classical, two-dimensional fractal, and 3DSG configurations. Simulations were conducted for a uniform inflow at a Reynolds number of 4000 within a conduit representative of a wind tunnel. Comparative analyses revealed that the 3DSG with a 24% blockage ratio produced turbulence intensities and Reynolds stresses comparable to those generated by classical and fractal grids with substantially higher blockage ratios. These findings advance the understanding of turbulent flow, highlighting the potential of sparse multiscale grids for efficient turbulence production and their applicability in the design of flow-sensitive engineering systems.