Toward one-dimensional turbulence subgrid closure for large-eddy simulation

Randall McDermott, University of Utah

A new method to close the large eddy simulation (LES) equations using the one-dimensional turbulence (ODT) model of Kerstein et al. [1] is presented. In contrast to traditional eddy-viscosity closures, LES/ODT explicitly models subgrid inertial cascading (a totally inviscid process), which is responsible for practically all of the energy transfer off the LES grid in high Reynolds number flows. ODT is, in some respects, a one-dimensional surrogate for a direct numerical simulation (DNS), capturing detailed spatial and temporal structure and resolving the viscous scales in the flow. The method proves to be a versatile and robust subgrid closure. ODT is especially useful in handling problems that have plagued LES, namely near wall modeling and subgrid mixing. Additionally, while capturing detailed subgrid structure, this method does not become cost prohibitive at high Reynolds numbers. Results are compared with experimental data for decaying isotropic turbulence and DNS data for channel flow. 



[1] Kerstein, A.R., Ashurst, W.T., Wunsch, S. and Nilsen, V., One-dimensional turbulence: vector formulation and application to free shear flows. J. Fluid Mech. (2001) 447, 85-109.

Abstract Author(s): R. McDermott, R. Schmidt, A. Kerstein and P. Smith