An efficient very large eddy simulation model for simulation of turbulent flow

Abstract

SUMMARYAmong the various hybrid methodologies, Speziale's very large eddy simulation (VLES) is one that was proposed very early. It is a unified simulation approach that can change seamlessly from Reynolds Averaged Navier–Stokes (RANS) to direct numerical simulation (DNS) depending on the numerical resolution. The present study proposes a new improved variant of the original VLES model. The advantages are achieved in two ways: (i) RANS simulation can be recovered near the wall which is similar to the detached eddy simulation concept; (ii) a LES subgrid scale model can be reached by the introduction of a third length scale, that is, the integral turbulence length scale. Thus, the new model can provide a proper LES mode between the RANS and DNS limits. This new methodology is implemented in the standard k − ϵ model. Applications are conducted for the turbulent channel flow at Reynolds number of Reτ = 395, periodic hill flow at Re = 10,595, and turbulent flow past a square cylinder at Re = 22,000. In comparison with the available experimental data, DNS or LES, the new VLES model produces better predictions than the original VLES model. Furthermore, it is demonstrated that the new method is quite efficient in resolving the large flow structures and can give satisfactory predictions on a coarse mesh. Copyright © 2012 John Wiley & Sons, Ltd.

The State of the Art of Hybrid RANS/LES Modeling for the Simulation of Turbulent Flows

“…The hybrid RANS/LES simulation provided similar results as LES and better than unsteady RANS. Recently, Han and Krajnovic [117, 118] have built a new function F R inspired both by Eqs. 92 and 93 as where β 1 = 1.22 × 10 −3 , β 2 = 2.0 × 10 −3 and n = 2.…”

Investigation of the Flow Over an Oscillating Cylinder With a Very Large Eddy Simulation Model

“…The coefficients and a detailed description of this model can be found in [8]. This eddy-viscosity-based model yields better results in comparison to other RANS models for wall-bounded flows [8]. Since the predictive accuracy of VLES depends on the specific RANS turbulence model [6], the application of the ζ − f model as a background RANS model for VLES appears to be promising.…”

“…The coefficients and a detailed description of this model can be found in [8]. This eddy-viscosity-based model yields better results in comparison to other RANS models for wall-bounded flows [8].…”

“…Therefore, Han et al [7] provided a modified VLES approach. This new hybrid model shows high efficiency and robustness in many applications already on relatively coarse grids [2], [7], [8].…”

Investigation of the sensitivity of turbulent closures and coupling of hybrid RANS‐LES models for predicting flow fields with separation and reattachment

“…No significant differences between the linear and non-linear hybrid models were observed for the grids tested. The periodic hills simulations have also been performed using shear stress transport (SST)-DDES [37], partially averaged Navier-Stokes [38], partially integrated transport modeling and segregated modeling [39], and flow simulation methodology [12] approaches. The periodic hills simulations have also been performed using shear stress transport (SST)-DDES [37], partially averaged Navier-Stokes [38], partially integrated transport modeling and segregated modeling [39], and flow simulation methodology [12] approaches.…”