Investigation of Unsteady Control Surface Aerodynamics on a 2D Supercritical Airfoil Model

We present experimental and numerical investigations of steady and unsteady transonic flow past a 2-d supercritical airfoil equipped with a dynamically deflectable trailing edge flap of 25% chord length. Within the project COSDYNA an experimental data base was created for CFD code validation purposes. It includes steady and unsteady test cases for Mach numbers between 0.5 and 0.82. The unsteady cases comprise global pitch oscillations as well as pure flap oscillations for various excitation frequencies and amplitudes. In this paper DLR’s URANS solver TAU is used for comparative two-dimensional steady and unsteady computations. At this, we focus on five forced harmonic flap oscillation test cases, each for the reduced frequencies 0.1, 0.3 and 0.7. The overall agreement is shown to be satisfactory, even for separated flows