Aerodynamic analysis of high-lift airfoils by a dual-time integration method with upwind splitting

A dual time-step integration method with a preconditioned upwind scheme for the simulation of low Mach number flow is applied to an aerodynamic analysis of high-lift airfoils. Third-order flux extrapolation in conjunction with Roe´s (1981) flux splitting is chosen for spatial discretization. An implicit real-time discretization is used and the governing equations are evaluated by a two-stage Runge-Kutta scheme, while converged solutions are calculated in each pseudo-time-step. Also, local time stepping and residual smoothing methods are implemented to accelerate convergence. Aerodynamic loading of high-lift systems, including an oscillating NACA0012 airfoil and a NACA4412 airfoil with a Gurney flap, are simulated in this study. The simulated results show that the numerical predictions agree with the validated computed results or experimental data. The performance statistics of parallelization and vectorization on Cray and Fujitsu vector machines for the current study are also investigated