Accession Number : ADA289937

Title :   Numerical Experiments on the Flow Past a Circular Cylinder at Sub-Critical Reynolds Number,

Corporate Author : STANFORD UNIV CA THERMOSCIENCES DIV

Personal Author(s) : Beaudan, Patrick ; Moin, Parviz

PDF Url : ADA289937

Report Date : DEC 1994

Pagination or Media Count : 262

Abstract : The performance of the dynamic subgrid-scale eddy-viscosity model and the suitability of high-order accurate, upwind-biased numerical methods for large eddy simulations of complex flows are investigated in the case of the turbulent wake behind a circular cylinder at Reynolds number 3,900, based on freestream velocity and cylinder diameter. The numerical method consists of high-order upwind-biased finite difference techniques applied to the compressible Navier-Stokes equations written in generalized coordinates. Integration in time is done using a fully implicit, second-order accurate iterative technique. The results of three fifth-order accurate simulations performed on identical grids with the least-squares version of the dynamic model, the fixed-coefficient Smagorinsky model, and with no subgrid-scale model are compared in the first 10 diameters of the wake. The impact of three-dimensionality is also examined via two and three-dimensional calculations without a subgrid-scale model. The effect of numerical dissipation is investigated by comparing two simulations using upwind-biased schemes, the first being fifth-order, and the second seventh-order accurate. It is found that the near-wake is highly three-dimensional at this Reynolds number. It contains pairs of counter-rotating streamwise vortices, the effect of which cannot be reproduced in two-dimensional calculations. Three-dimensional computations are essential for predicting flow statistics of engineering interest. (AN)

Descriptors :   *EDDIES(FLUID MECHANICS), *COMPUTATIONAL FLUID DYNAMICS, *VISCOUS FLOW, VELOCITY, MATHEMATICAL MODELS, COMPUTERIZED SIMULATION, EXPERIMENTAL DATA, GRIDS, BOUNDARY LAYER, DISSIPATION, TURBULENCE, VORTEX SHEDDING, THREE DIMENSIONAL, FINITE DIFFERENCE THEORY, COMPRESSIBLE FLOW, CYLINDRICAL BODIES, WAKE, NUMERICAL METHODS AND PROCEDURES, HEAT FLUX, NAVIER STOKES EQUATIONS, FREE STREAM, BIAS, LAMINAR FLOW, REYNOLDS NUMBER.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE