In this study, the accuracy of structured and unstructured mesh CFD codes in simulating the flow around a threeelement high-lift configuration (slat, main wing, and flap) is assessed, and mesh dependency and effect of turbulence models are studied. In the first part of the study, the results of two structured mesh CFD codes and an unstructured mesh CFD code using the same turbulence model are compared and discussed. A mesh refinement approach is also used to examine the dependency of numerical accuracy on the density of unstructured meshes. By properly distributing mesh points in an unstructured mesh, the detail in flow physics is obtained. It is also shown that the quantitative prediction of the vortex in the slat cove is an important factor that affects accuracy. In the second part of the study, three turbulence models are compared using one of the structured mesh CFD codes. All turbulence models can produce similar flowfields. However, several differences are seen in the separated regions, especially in the slat cove. Commonly used turbulence models, Spalart-Allmaras model and Menter's SST model, produce similar aerodynamic forces at lower angles of attack. At higher angles of attack, the SST model gives better results for the present computations. It is found that the maximum lift and the angle at which the stall occurs are very sensitive to the turbulence model.
The objectives of this study are to assess the accuracy of CFD codes, investigate the effect of turbulence models as applied to the flow around high-lift devices, and increase the knowledge for computing this kind of flow. CFD validation is conducted for a two-element airfoil and compared with a wind tunnel test to predict the aerodynamic forces, including the maximum lift and the stall angle. Sensitivity to grid density and influence of the grid extent are investigated. Four RANS codes with the same turbulence model are tested and computational results are compared with each other. Three commonly used turbulence models implemented in a CFD code are applied to investigate the effects of turbulence models for this kind of high-lift flow.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.