Turbulence Model Data Derived from Direct Numerical Simulations

Abstract

With the aid of direct numerical simulation results, modelling of turbulence is examined. The near-wall region is of special interest. In this paper we concentrate on the modelling of the kinetic energy equation used in low-Reynolds-number turbulence models. The damping of the turbulent viscosity is compared with different models in order to elaborate the mechanisms of this phenomenon. The gradient model for the turbulent diffusion term is tested and found to work well in the case of turbulent channel flow. Simple wall boundary conditions for the dissipation $ε$ are tested using the numerical database. Furthermore, for different quantities the limiting near-wall behaviour is computed, which could be useful for evaluating the limiting behaviour of models or model assumptions.