Evaluation of Traditional and Shock-Confining LES Filters using DNS Data of Compressible Turbulence

TitleEvaluation of Traditional and Shock-Confining LES Filters using DNS Data of Compressible Turbulence
Publication TypeConference Papers
Year of Publication2007
AuthorsTaylor EM, Grube NE, Martin, M.P
Conference NameProceedings of 18th AIAA Computational Fluid Dynamics Conference
Date Published2007///

Uniformly high-order-accurate filtering of fluid flow properties in the presence of shocksand shocklets is theoretically susceptible to the same problem that afflicts uniformly high-
order-accurate numerical methods for approximating the convective terms of the Navier-
Stokes equations: the introduction of new, non-physical extrema near discontinuities. Ex-
tensive investigations have been conducted into myriad types of shock-capturing methods,
which adaptively decrease their order of accuracy within shock-containing regions in order
to maintain accuracy and stability over time. Inspired by such work, Grube et al. (AIAA
2007-4198) have proposed the conceptually similar idea of “shock-confining” filtering (SCF)
for compressible large-eddy simulations (LES), in which a class of linear filters is subject
to adaptive adjustments based on smoothness information provided by a weighted essen-
tially non-oscillatory (WENO) method. In the current work, we utilize the turbulent flow
fields produced by direct numerical simulations (DNS) of shock/isotropic-turbulence inter-
action to perform preliminary a priori testing of these shock-confining filters against the
corresponding linear filters. Although additional study, both a priori and a posteriori, is
required to verify the necessity and suitability of SCF for LES, we conclude that linear
filtering can indeed create serious qualitative discrepancies in global flow characteristics,
discrepancies that are avoided by the use of SCF.