Parallel spatial direct numerical simulation of boundary-layer flow transition on IBM SP1

摘要

The spatially evolving disturbances that are associated with laminar-to-turbulent transition in three-dimensional boundary-layer flows are computed with the PSDNS code on an IBM SP1 parallel supercomputer. By remapping the distributed data structure during the course of the calculation, optimized serial library routines can be utilized that substantially increase the computational performance. Although the remapping incurs a high communication penalty, the parallel efficiency of the code remains above 40 percent for all performed calculations. By using appropriate compile options and optimized library routines, the serial code achieves 52-56 Mflops on a single node of the SP1 (45 percent of theoretical peak performance). The actual performance of the PSDNS code on the SP1 is evaluated with a 'real world' simulation that consists of 1.7 million grid points. Comparisons to the Cray Y/MP and Cray C-90 are made for this large scale simulation.