Comparison of RANS Simulations of Multi-Element High-Lift Configurations

Abstract

In this study, flow computations are performed on three-dimensional high-lift configurations on multi-block structured and unstructured meshes with two turbulence models, Spalart-Allmaras model and Menter’s Shear Stress Transport model. Two kinds of three-element trapezoidal wings with full-span flap or part-span flap are computed. The objectives of this paper are to investigate the mesh dependency and the effect of turbulence models and improve the reliability in simulating the flow around high-lift devices. First, the mesh dependency on unstructured meshes is investigated and the results on structured and unstructured meshes using the same turbulence model, Spalart-Allmaras model, are compared. Importance of the mesh resolution to resolve the separated corner flows near the wing-fuselage junction is shown to improve the accuracy of computational results. Next, difference of flows by turbulence models is evaluated using the unstructured mesh CFD code. The effect on the prediction of the stall is discussed. It is shown that the maximum lift and the angle at which it occurs are very sensitive to turbulence model and Menter’s model gives better results at higher angle of attack in the present computations.