A New Wall Model for Large Eddy Simulation of Separated Flows

Wall-modelling strategies in large eddy simulation of separated high- Reynolds-number flows

The need to develop wall-modelling strateguiess arises from the fact that the detailed resolution of near-wall turbulence becomes untenably expensive as the Reynolds number of the flow increases to level approaching that pertaining to real-world applications. The problem is conveyed by Fig. 1, taken from Piomelli & Balaras (2002). The figure shows that, when ReL (say, that based on the boundary...

A new eddy-based model for wall-bounded turbulent flows

Wall-modeled large-eddy simulation of a separated flow over the NASA wall-mounted hump

Wall-modeled large-eddy simulation (WMLES) attempts to provide a predictive but affordable framework for LES by modeling the effect of the computationally demanding inner-layer structures on the outer-layer flow. The grids employed in LES are designed to resolve the outer layer only, thereby reducing the computational cost of LES significantly to affordable levels. The saving in the computation...

Mixed Large-Eddy Simulation Model for Turbulent Flows across Tube Bundles Using Parallel Coupled Multiblock NS Solver

In this study, turbulent flow around a tube bundle in non-orthogonal grid is simulated using the Large Eddy Simulation (LES) technique and parallelization of fully coupled Navier – Stokes (NS) equations. To model the small eddies, the Smagorinsky and a mixed model was used. This model represents the effect of dissipation and the grid-scale and subgrid-scale interactions. The fully coupled NS eq...

A New Model for Prediction of Heat Eddy Diffusivity in Pipe Expansion Turbulent Flows

A new model to calculate heat eddy diffusivity in separating and reattaching flows based on modification of constant Prt is proposed. This modification is made using an empirical correlation between maximum Nusselt number and entrance Reynolds number. The model includes both the simplicity of Prt=0.9 assumption and the accuracy of two-equation heat-transfer models. Furthermore, an appropriate l...