Transient aerodynamic response of an airfoil to a moving plane flap and a rapidly deploying spoiler is numerically investigated using two-dimensional Euler and turbulent Navier-Stokes equations, respectively. The control surface moving relative to a stationary airfoil is treated by an overset grid bounded by the Dynamic Domain-Dividing Line (DDDL) the concept of which is developed in this paper. As the Chimera grid method, both conservative and conventional method are used and applied to several cases of the supersonic cylinder in order to verify them. The validation of the Euler code with conservative Chimera grid is conducted for the two cases : the oscillating NACA 0012 airfoil and the transient ramp pitching airfoil. The flowerfields around RAE 2822 airfoil are calculated using the Navier-Stokes equations adopting three turbulence models.
The unsteady aerodynamic characteristics of the plane flap moving sin-wave form are investigated using Euler equations. The effects of the slot between airfoil and flap are examined. The aerodynamic response parameters such as delay time, settling time, and time to the lift peak are investigated with the variations of Mach number and deflection time.
An algebraic Baldwin-Lomax model, a Wilcox k-ω model, and a SST k-ω turbulence model are used for the unsteady separated flow due to the spoiler motion. The fluid-dynamic mechanism of the adverse lift due to the rapidly deploying spoiler is explaned.The effects of the deploying rate, the location, and the hinge gap of a spoiler on the initial aerodynamic behavior of the airfoil are elaborated. The present computation about the stationary as well as moving spoilers gives results well comparable to the existing experimental data.
