Abstract:
The large eddy simulation method based on structured patched mesh was developed to accurately predict the laminar separation phenomena under low Reynolds number conditions. The Favre averaged Navier-Stokes equations are solved, and various sub-grid scale models are utilized. The AUSM and high order WENO scheme are adopted for spatial discretization, and explicit and implicit methods are used for time integration. Through the simulation of the laminar separation flow around the SD7003 airfoil at Reynolds number 60 000 and angle of attack 4°, the influence of numerical schemes, sub-grid models, and mesh resolution on the computed results were compared and analyzed. The computational results show that, the computational meshes are effective for resolving the small scale flow structures, and the implicit large eddy methodology which utilizes the AUSM scheme and the dual time method can predict the complex flow phenomena of separation, transition, and reattachment accurately. The computed averaged pressure coefficients and Reynolds stress agree well with the computational and experimental data in literatures. The comparison with the results of transition model further reveals that, the developed large eddy simulation method can accurately predict the unsteady evolution of laminar separated flow on low Reynolds number airfoils. The present study establishes an effective numerical simulation method for the future research.