Turbulence Modeling for Low-Reynolds-Number Flows

A modification of the kappa-omega shear-stress-transport turbulence model is presented in this paper with the aim to improve the simulation of flows at a low Reynolds number. For this purpose, the incompressible flow at Reynolds number 6 x 10(4), around the Selig-Donovan 7003 airfoil, is investigated by using several turbulence models. The focus is placed on the kappa-omega shear-stress-transport turbulence model: a model very reliable for transonic flows but for which the application to low-Reynolds-number flows has been questioned. The limits of this model are analyzed in detail. The simulation of the laminar bubble arising on the SD 7003 airfoil has been remarkably improved by the proposed modification. In addition, the accuracy of the kappa-omega shear-stress-transport turbulence model has been preserved in the transonic regime at a high Reynolds number, as shown by the simulations of the flow around the RAE M2155 wing. Large-eddy simulations of the flow around the Selig-Donovan 7003 airfoil have also been performed and presented in the paper. The large-eddy-simulation data are used as a reference for the results achieved by the Reynolds-averaged Navier-Stokes method. The computed aerodynamic coefficients are compared with some available experimental data.