An explicit algebraic subgrid-scale scalar flux model for large eddy simulation

Författare: Rasam, A., Marstorp, L..M., Brethouwer, G.B., Johansson, A.V.J.
Dokumenttyp: Konferens
Tillstånd: Publicerad
Tidskrift: Proc. of 8th Int. ERCOFTAC Symp. on Engineering Turbulence Modelling and Measurements (ETMM8)
Volym: 3   884-889
År: 2010


A new subgrid-scale (SGS) scalar flux model is developed for large eddy simulation of turbulent flows. The new model uses an explicit algebraic formulation for the SGS scalar flux, similar to the explicit algebraic scalar flux model (EASFM) of Wikström et al. (2000) for Reynolds averaged Navier Stokes (RANS) simulations. The model is verified for turbulent channel flow with and without rotation and the results are in good agreement with DNS data. In comparison with the eddy diffusivity model, the new model predicts the magnitude and the anisotropy of the scalar variance subgrid-scale dissipation more realistically. For rotating channel flow, the model predicts the scalar fluxes near the wall more accurately. Furthermore, the model is less resolution dependent than the eddy diffusivity model for the prediction of the scalar flux.