Ja. Domaradzki et Em. Saiki, A SUBGRID-SCALE MODEL-BASED ON THE ESTIMATION OF UNRESOLVED SCALES OFTURBULENCE, Physics of fluids, 9(7), 1997, pp. 2148-2164
A new method for large eddy simulations is described and evaluated. In
the proposed method the primary modeled quantity is the unfiltered ve
locity field appearing in the definition of the subgrid-scale stress t
enser. An estimate of the unfiltered velocity is obtained by expanding
the resolved large-scale velocity held to subgrid-scales two times sm
aller than the grid scale. The estimation procedure consists of two st
eps, The first step utilizes properties of a filtering operation and t
he representation of quantities in terms of basis functions such as Fo
urier polynomials. In the second step, the phases associated with the
newly computed smaller scales are adjusted In order to correspond to t
he small-scale phases generated by nonlinear interactions of the large
-scale field. The estimated velocity field is expressed entirely in te
rms of the known. resolved velocity field without any adjustable const
ants. The modeling procedure is evaluated in a priori analyses using d
irect numerical simulation results of channel flow at low Reynolds num
ber and in actual large eddy simulations of channel flow at two differ
ent Reynolds numbers. In all cases, the new model performs better than
or comparable to classical eddy viscosity models for the majority of
physical quantities. Ln particular, all components of the subgrid-scal
e stress tensor are predicted accurately and the procedure naturally a
ccounts for backscatter without any adverse effects on the numerical s
tability. (C) 1997 American Institute of Physics.