Parallel computation of turbulent fluid flows with the piecewise-parabolic method

The chapter uses the piecewise-parabolic method (PPM) gas dynamics code on large NSF TeraGrid parallel systems as well as on SMP and cluster systems in a lab, to simulate turbulent flows at grid resolutions of 1024³ and 2048³ cells. The chapter discusses both single- and two-fluid flows with statistically homogeneous and unstable shear layer initial conditions. The purpose of these simulations is to capture detailed datasets that allow design and validation of sub grid-scale turbulence models. The parallel code implementation manages a set of shared data objects, each describing a sub domain of the problem. These data objects can be instantiated as either disk files or in-memory objects on a designated set of network nodes that serve them to computational processes over a cluster network. When implemented as disk files, large problems can be run, at no loss in performance, on systems that do not have sufficient memory to hold a complete description of the problem state.