Pseudo-stochastic simulation of turbulent channel flows with near-wall modelling
Abstract
The pseudo-stochastic model recently proposed by Mémin (2014) is investigated and compared with the large-eddy simulation methodology. The theoretical analysis shows that this model is a generalisation of the eddy-viscosity model, which does not undergo the same restrictive physical assumptions and describes physical phenomena usually not considered (turbophoresis and turbulent com-pressibility). Numerical simulations of turbulent channel flows are performed. In order to better reproduce the turbulence anisotropy, a near-wall damping function is derived and successfully validated: the damping is imposed only on wall-normal direction (minimal constraint) and it requires to set a single parameter (reduced empirical content). Simulations show the accuracy of the new model, especially when the computational grid becomes coarse. A weak turbophoresis phenomenon is detected near the wall, while turbulent compress-ibility effects appear to be possibly related to the streaks structures.
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