Developing code-friendly variant of V2F turbulence model

Abstract

Relevant modifications to the code-friendly variant of v¯2−f turbulence model is proposed that accounts for the distinct effects of low-Reynolds number and near-wall turbulence. It incorporates compatible formulations for inter-dependent coefficients Cϵ(1,2) and σ(k,ϵ) to amplify the level of dissipation in non-equilibrium flow regions, thus reducing the turbulent kinetic energy and time/length scale magnitudes to improve prediction of adverse pressure gradient flows, involving flow separation and reattachment. A non-linear eddy-viscosity coefficient with a realizable eddy-viscosity bound that may enhance the predicted accuracy for complex flows, is introduced with the present model. Coefficients of the elliptic-relaxation equation are constructed such as to preserve the anisotropic characteristics of turbulence, encountered in rotational and irrotational flows. Fully-developed turbulent channel and flat-plate flows are computed to validate the model ability in replicating the near-wall turbulence. An asymmetric plane diffuser flow is simulated to verify the model accuracy in capturing non-equilibrium flows with separation and reattachment. The Computation of flow over a three-dimensional (3D) axisymmetric hill is presented, rectifying the model competency in predicting an adverse-pressure-gradient flow with 3D turbulent separation. Model predictions are compared with the widely used SST (shear stress transport) k−ω model; a good correlation is obtained between the current model and DNS/experimental data.