MPI Scalability of a Large Memory LES Code

Abstract — Large eddy simulations (LES) of co-flowing round jets with 33.6 million grid points are carried out using 16 Sun 1 GHz UltraSPARC III Cu processors. An in-depth processor scalability analysis is carried out for an MPI based code for a finite-volume solution of time dependent Navier-Stokes equations. The solver is based on a second-order structured staggered grid discretization, second-order time advancement, and a multi-grid Poisson equation for pressure. Particular attention is paid to the effect of initial conditions on the spatial development of the co-flowing jet at a Reynolds number of 7,300. A co-flow velocity to initial jet centreline velocity ratio of 1:11 and a coflow to initial jet diameter ratio of 35:1 are used to match the flow cases of [12]. The ¢¡¤£¦¥¨§ © �¡�£ simulation volume, where £ is the orifice diameter at the jet inlet, is divided int