A DOMAIN-DECOMPOSITION MESSAGE-PASSING APPROACH TO TRANSIENT VISCOUS INCOMPRESSIBLE-FLOW USING EXPLICIT TIME INTEGRATION

This paper discusses the design and implementation of solution algorit hms suitable for performing transient, incompressible viscous flow sim ulations on massively parallel computers. The finite element formulati on for incompressible flow along with the ad-hoc modifications for exp licit time integration are discussed with an emphasis on implementatio n aspects for achieving scalable, parallel computations. The issues as sociated with a domain-decomposition message-passing paradigm are pres ented in the context of explicit time integration and the solution of a pressure Poisson equation using a staggered grid. An element-by-elem ent conjugate gradient algorithm for the pressure equation is outlined with a parallel sub-domain preconditioner. Sample calculations are pr esented with scaled speedup and efficiency results to demonstrate the scalability of the domain-decomposition message-passing approach.