Numerical and Experimental Investigations of Unsteady Flows under Deep Dynamic Stall Conditions

摘要

With increased advance ratios, the retreating blades of modern helicopters encounter flow environments with severe separation and vortex shedding which are known as deep dynamic stall conditions. For the numerical treatment of the problem, a time-accurate code based on the 2D-Navier-Stokes equations has been applied. The experimental investigation of the instaneous flowfield was carried out by means of a Particle Image Velocimetry (PIV), in two different wind tunnel facilities: The low-speed wind tunnel of the German-French Institute, St.Louis (ISL) and the High Speed Wind Tunnel (HKG) of the DLR in Gottingen. For each wind tunnel, a test set-up for oscillating models has been constructed and used throughout the measurements. Numerical and experimental data obtained under nearly the same conditions are presented and compared.