Prediction of transitional and fully turbulent flow using an alternative to the laminar kinetic energy approach

摘要

This paper presents a new eddy-viscosity turbulence model for prediction of laminar, transitional and turbulent flow, as an alternative to the popular laminar kinetic energy framework. The model represents a conceptually different description of the transition process, in which the pressure-strain terms of the Reynolds stress budget are suppressed in pretransitional flow regions, and transition is viewed as activation of the pressure-strain terms. This concept has been implemented using an existing linear-eddy viscosity Reynolds-averaged Navier-Stokes transitional model as a baseline, which has been modified to more accurately capture the physics of fully turbulent free shear flows. The model is tested for several boundary layer and free shear flow test cases. The simulations show engineering accurate results, qualitatively equivalent to the baseline transition-sensitive model for boundary layer test cases, and substantially improved over the baseline model for fully turbulent free shear flows. The results suggest that the new model formulation may have a wider range of application than the baseline model for complex transitional and turbulent flows.