A stochastic subgrid model with application to turbulent flow and scalar mixing
2007 (English)In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 19, no 3, 035107- p.Article in journal (Refereed) Published
A new computationally cheap stochastic Smagorinsky model which allows for backscatter of subgrid scale energy is proposed. The new model is applied in the large eddy simulation of decaying isotropic turbulence, rotating homogeneous shear flow and turbulent channel flow at Re-tau=360. The results of the simulations are compared to direct numerical simulation data. The inclusion of stochastic backscatter has no significant influence on the development of the kinetic energy in homogeneous flows, but it improves the prediction of the fluctuation magnitudes as well as the anisotropy of the fluctuations in turbulent channel flow compared to the standard Smagorinsky model with wall damping of C-S. Moreover, the stochastic model improves the description of the energy transfer by reducing its length scale and increasing its variance. Some improvements were also found in isotropic turbulence where the stochastic contribution improved the shape of the enstrophy spectrum at the smallest resolved scales and reduced the time scale of the smallest resolved scales in better agreement with earlier observations.
Place, publisher, year, edition, pages
2007. Vol. 19, no 3, 035107- p.
LARGE-EDDY SIMULATION; BACKSCATTER; VISCOSITY; ENERGY
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-8696DOI: 10.1063/1.2711477ISI: 000245318500019ScopusID: 2-s2.0-34047223580OAI: oai:DiVA.org:kth-8696DiVA: diva2:14084
QC 201008252008-06-052008-06-052010-08-25Bibliographically approved