Simulation of flow separation at the wing-body junction with different fairings

The numerical simulation and analyses of the flow separation at the wing-body junction with different designed fairings for a transporter are carried on by using a viscous flow solver based on hybrid unstructured meshes in this paper. In the process of generating hybrid meshes, the Pirzadeh advancing-layer method is improved to generate high-quality hybrid prismatic/pyramid/tetrahedral unstructured meshes in the boundary-layer region, and the advancing-front method is used to construct isotropic tetrahedral meshes in the residual flow region. Navier-Stokes equations are solved using a cell-centered unite volume method with the Spalart-AUmaras one-equation turbulence model. According to the Batina and Tomaro time-stepping theories, time is marched by means of an implicit GaussSeidel relaxation procedure, which is constructed by using the first-order linearizing of the flux vector and the maximal eigenvalue splitting of the flux Jacobian matrix. With local time stepping and implicit residual smoothing, artifice is used to accelerate convergence. The agreement of the computational results and the experimental measurements proves good capability of simulating wing-body interferences on a transporter by using a viscous flow solver based on hybrid unstructured meshes. In addition, numerical study indicates that wing-body fairing could suppress flow separation at the wing-body junction, increase the lift-drag ratio, and improve the aerodynamic performance.