Accession Number : ADA289919

Title :   Scalability Study of Parallel Spatial Direct Numerical Simulation Code on IBM SPI Parallel Supercomputer.

Descriptive Note : Final rept.,

Corporate Author : INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA

Personal Author(s) : Hanebutte, Ulf R. ; Joslin, Ronald D. ; Zubair, Mohammad

PDF Url : ADA289919

Report Date : AUG 1994

Pagination or Media Count : 21

Abstract : The implementation and the performance of a parallel spatial direct numerical simulation (PSDNS) code are reported for the IBM SP1 supercomputer. The spatially evolving disturbances that are associated with laminar-to-turbulent in three-dimensional boundary-layer flows are computed with the PS-DNS code. 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 SPi (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. One time step of this simulation is calculated on eight nodes of the SP1 in the same time as required by a Cray Y/MP for the same simulation. The scalability information provides estimated computational costs that match the actual costs relative to changes in the number of grid points.

Descriptors :   *COMPUTER PROGRAMS, *COMPUTERIZED SIMULATION, *SUPERCOMPUTERS, *THREE DIMENSIONAL FLOW, DATA BASES, PEAK VALUES, OPTIMIZATION, COMPUTATIONS, DISTRIBUTED DATA PROCESSING, COST ESTIMATES, EFFICIENCY, PARALLEL PROCESSORS, NODES, COSTS, GRIDS(COORDINATES), FORTRAN, COMMUNICATION AND RADIO SYSTEMS, VISCOUS FLOW, LIBRARIES, INCOMPRESSIBLE FLOW, PENALTIES, BOUNDARY LAYER FLOW.

Subject Categories : Computer Programming and Software
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE