The Navier-Stokes equations are solved with the second-order LU-SGS-τTS implicit time-stepping method. The sixth-order symmetric TVD scheme with fifth-order WENO interpolation based on Roe is applied to the convection terms. A boundary layer flow around a flat plate, a low speed flow around the Aerospatial A-profile at high incidence and a transonic flow with shock/boundary interaction around RAE2822 airfoil are computed by Baldwin-Lomax and Spalart-Allmaras models with the transition criterion, respectively. The results show that the approaches capture the transition automatically.

A fully implicit Lower-Upper-Symmetric-Gauss-Seidel (LU-SGS) with pseudo time sub-iteration and the modified Jameson's central scheme are applied to solve thin layer Navier-Stokes(N-S) equations with laminar hypothesis and Baldwin-Lomax(B-L) model for the vortical flows around delta wings at high angles of attack (AOA).To validate the codes,a 65 degree swept delta wing is computed in transonic cases,where M_∞=0.85,α=10°,20° and Re=5×10⁶.Then asymmetrical vortex breakdown flows with M_∞=0.3,and Re=1.3×10⁶,at high AOA around an 80° swept delta wing are presented and discussed.The computational results are compared with experimental data available and good agreement is achieved.

Grid generation and flow analysis methods for multi-element airfoil based on multi-block point-to-point patched grid technology are developed. Some strategies are developed to improve the efficiency, accuracy and applicability of the method.Several flow cases about multi-element airfoils are computed with the present method in order to validate it. Numerical results are in agreement with experiment data. Flow field visualization shows that the present method has good resolution in flow details.

Because of the complexities in both configurations and flow phenomena,there are great difficulties in the numerical simulation of flow about wing with lift-enhancing devices and control surfaces.By using cell-centered finite volume method,it deals with Renolds-averaged Navier-Stokes equations on multi-block structural grids generated by elliptic method.Two kinds of patching schemes,point-to-point and patch-on-common-surface,are employed to establish the information exchange among blocks.In the later one,the overlap cell area weighted interpolation is used to guarantee the conservation.Ramshaw algorithm is also used to pre-determine the overlap areas.Flow fields about multi-element airfoils and delta wing with deflected flap are computed with the present method.Numerical results are all in good agreement with experiment data.Flow field visualization shows the present method has good resolution in flow details.