Unsteady flow simulation using an MIMD computer

Numerical simulations of unsteady flows require algorithms with high order of accuracy in both time and space and correspondingly vast computer resources, because flow properties may have to be computed for large times before significant information can be extracted from them. Massively parallel computers are particularly well suited for these simulations if the computational domain could be mapped on to the processors while maintaining high efficiency and time synchronization between the nodes of the MIMD computer. Certain aspects of the implementation of a time-accurate algorithm to solve the Navier-Stokes equations on structured grids, using a massively parallel processor, are presented in this paper along with results for two problems: (1) the changing characteristics of the near-wake flow behind a cylinder as a function of Reynolds number and (2) dynamics of vortex pairing in free-shear layers