Numerical Investigation of Energy Transfer and Subgrid-Scale Eddy Viscosity in Homogeneous, Isotropic and Shear Turbulence.

摘要

Numerical solutions to the Navier-Stokes equations for a 3-D, time-dependent, highly-symmetric flow have been completed. An effective resolution of up to 10243 collocation points (341 modes after dealiasing) is attained within the memory on the 256 MW CRAY-2 at Kirtland AFB and the C90 at the Pittsburgh Supercomputer Center. These simulations constitutes the highest resolution runs made to date. One of the primary purposes of the work was to create a data base from which a detailed energy transfer and triad analysis could be made by Andrzej Domaradzki at USC. The data base has been made, and runs for Reynolds numbers of 500, 1000, 2000 and 5000 have been stored on tape. We shall give some information concerning the turbulent flows later in this report. The other purpose of this work is to try to understand the transition process through which the flow becomes turbulent. Our early-time analysis of the data base of runs was concerned with this problem, and hence most of this report will deal with our findings. We also attach a manuscript on this subject that will be published shortly in The Physics of Fluids. Turbulent flows, Transition, Numerical simulation.