Showing papers by "Paul Fischer published in 1996"

Direct numerical simulation of three-dimensional flow and augmented heat transfer in a grooved channel

Abstract: Direct numerical simulations of three-dimensional flow and augmented convective heat transfer in a transversely grooved channel are presented for the Reynolds number range 140 < Re < 2000. These calculations employ the spectral element technique. Multiple flow transitions are documented as the Reynolds number increases, from steady two-dimensional flow through broad-banded unsteady three-dimensional mixing. Three-dimensional simulations correctly predict the Reynolds-number-independent friction factor behavior of this flow and quantify its heat transfer to within 16 percent of measured values. Two-dimensional simulations, however, incorrectly predict laminar-like friction factor and heat transfer behaviors

A commercial CFD application on a shared memory multiprocessor using MPI

Abstract: Publisher Summary This chapter discusses the implementation of a parallel spectral element computational fluid dynamics (CFD) application, Nekton, on the Silicon Graphics (SGI) Power Challenge, using the newly defined Message Passing Interface (MPI) standard. This enables a smooth transition of a code designed for a distributed memory system to a shared memory parallel computer. Nekton was originally implemented using the NX message passing library. Nekton and the Power Challenge system are briefly described, followed by a discussion of the implementation of Nekton on a Power Challenge using MPI. The implementation of an improved pressure solver in Nekton which reduces the computation time significantly is discussed. Results from the analysis of two and three dimensional fluid flow problems are presented which show good parallel speedups and efficiencies with increasing number of processors. Factors which limit the speedup and efficiency and strategies to improve them are discussed. The chapter further suggests the modifications to the parallel implementation which will improve the computation to communication ratio through reduced latency.