Massively parallel implementation of a 3D vortex-boundary element method

Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge, MA 02139, USA

Abstract

Vortex-boundary element simulation of three-dimensional wall-bounded flows is performed on a massively parallel architecture using the data parallel paradigm. With proper optimization, implementation on the Thinking Machines CM5 is shown to yield over an order of magnitude speed-up over the Cray C90, using 128 processors. This makes the direct evaluation of the flow eld represented by up to 100 000 vortex elements feasible. In this paper, the CPU time and memory requirements for the direct evaluation of the vortical eld using three parallelization algorithms are compared. In addition, performance results for the evaluation of the vortical and potential velocities, and their gradients, are presented as a function of the number of vortex elements and the number of processing nodes. Finally, to demonstrate the capability of the developed method, preliminary results from the case of flow around a stationary, idealized trailer truck near the ground level at Re = 500 are presented.