Simulation of the 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, Pirzadeh's advancing-layer method is improved to generate high quality hybrid prismatic/pyramid/tetrahedral unstructured meshes in the boundary-layer region, and advancing-front method is used to construct isotropic tetrahedral meshes in the residual flow region. Navier-Stokes equations are solved using a cell-centered finite-volume method with Spalart-Allmaras one-equation turbulence model. And according to Bettina and Tomaro's theory, time is marched by means of an implicit Gauss-Seidel relaxation procedure, which is constructed by using the first-order linearizing of flux vector and the maximal eigenvalue splitting of flux Jacobian matrix. Withal local time stepping and implicit residual smoothing artifice are used to accelerate convergence. The consistence of the computational results and the experimental measurements proves the superior capability of simulating wing-body interferences on a transporter by using a viscous flow solver based on hybrid unstructured meshes. In addition, numerical studies indicate that wing-body fairing could allay flow separation at the wing-body junction, increase the lift-drag ratio and improve the aerodynamic performance.