Kinetic energy dissipation by
subgrid-scale stresses in turbulent flows
Charles Meneveau, Johns Hopkins University
One of the most important features of unresolved small scales in Large-Eddy-Simulation is the rate at which they extract kinetic energy from the resolved flow. We examine an experimental surrogate of the subgrid (SGS) dissipation rate, by means of high Reynolds number experimental data in the cylinder wake. Mean profiles are measured and compared a priori with several models (Smagorinsky, similarity model, dynamic Smagorinsky). More detailed comparisons are achieved by means of conditional averaging, both with outer intermittency and with the phase of coherent structures (Karman vortices) in the near wake. The results provide evidence that learning from resolved scales (such as in the dynamic and similarity models) leads to more realistic predictions than the constant-coefficient eddy-viscosity model, when turbulence is spatially complex and when coherent structures affect the SGS dynamics directly.
J. O'Neil and C. Meneveau 1997, "Subgrid-scale stresses and their modelling in a turbulent plane wake," J. Fluid Mech. 349, p. 253-293.
S. Liu, C. Meneveau and J. Katz 1994, "On properties of similarity subgrid-scale models as deduced from measurements in a turbulent jet," J. Fluid Mech. 275, p. 83.
C. Meneveau 1994, "Statistics of turbulence subgrid-scale stresses: Necessary conditions and experimental tests," Phys. Fluids A 6, p. 815.Back to Fluid Mechanics Seminar Page