RANS analysis of the low-Reynolds number flow around the SD7003 airfoil

摘要

This paper presents a numerical analysis of the incompressible flow at Reynolds number 6.0 × 10~4 around the Selig-Donovan 7003 airfoil. The airfoil performances have been computed by the Reynolds averaged Navier-Stokes equations and large eddy simulations. The airfoil stall and preliminary post-stall have been obtained by both the methods. Some limitations of the RANS turbulence models for low-Reynolds number flows have been overcome by the k-ω SST-LR model, a recent modification of the well-known SST model. Large-eddy simulations have also been performed for a more detailed analysis of the results. The relevance in the stall mechanism of the laminar separation bubble arising on the airfoil is highlighted. The stall occurs when the laminar bubble present in the leading edge zone and a separated region forming on the central part of the airfoil join together. The k-ω SST-LR model returns the same stall mechanism as the large eddy simulation. Flows at low-Reynolds numbers can be simulated by the RANS methods, but the choice of the turbulence model is crucial. The k-ω SST-LR model has provided results in good agreement with the large eddy simulation and the available experimental data.