Parallel speed-up of preconditioned fractional step navier-stokes solvers

Parallel performance of a fractional step Navier-Stokes solver is investigated. Parallelisation is performed using Message Passing Interface, with domain partitioning. Block preconditioning is applied to the solution of the pressure Poisson equation, which is often the bottleneck in the computation of the fractional step method. Preconditioners tested are classes of incomplete matrix decompositions and sparse approximate inverses. The computational domain is decomposed into eight parts of about equal size in terms of the number of cells, and solved on eight parallel processors. Several aspects of the parallelisation, such as domain splitting directions, speed-up and scalability of the preconditioners, are discussed.