A finite volume method for solving two-dimensional, incompressible, steady, Reynolds time-averaged equations is developed using a regular grid in a non-orthogonal body-fitted coordinate system. The numerical pressure fluctuation usually encountered in the regular grid is suppressed by a momentum interpolation method.
The conservation of physical quantities at the branch-cut, adopted in the present study in a C-type grid system is successfully satisfied by applying the zonal approach. A suitable differencing scheme for convection terms is very important for obtaining a reasonable numerical solution for the complex turbulent flow around an airfoil in a general coordinate system. Three different differencing schemes are tested to compare their characteristics: hybrid scheme, linear upwind differencing scheme(LUDS) and second-order upwind-central differencing-first-order upwind (SOUCUP).
In order to include the turbulent intermittency effect on the asymmetric wake flow behind the airfoil, the κ-ε-$\gamma$ equations proposed by Cho ＆ Chung have been numerically solved. The eddy viscosity is estimated by a function of κ, ε and $\gamma$. The results are compared with the available experimental data and with the results obtained by the standard κ-ε model. The turbulent intermittency affects considerably on the spreading rate of the wake and causes faster recovery of the wake center line velocity behind the airfoil, in comparison with that from the standard κ-ε model.
