AIAA Aerospace Sciences Meeting (25th) on Dynamic Stall Wake Interaction with a Trailing Airfoil Held in Reno, Nevada on 12-15 January 1987.

摘要

Experiments were conducted with tandem NACA 0015 airfoils placed in a wind tunnel 0.5 chord lengths apart. The leading airfoil was pitched about its quarter-chord axis at high constant rates from zero to 60 degrees incidence at chord Reynolds numbers from 50,000 to 200,000. These motions produced energetic dynamic stall vortex flows which impinged on the trailing airfoil fixed at zero degrees geometric angle of attack. Smoke-wire flow visualization and dynamic surface pressure measurement experiments were performed to study the effects of the unsteady vortical wakes on the trailing airfoil. The dynamic stall vortices produced by the pitching airfoil elicited complex, time-dependent secondary flow structures around the trailing airfoil which in turn produced large dynamic loads. These large transient loads may pose significant problems to the designers of control systems of aircraft generating or encountering such unsteady vortical flow structures. Keywords: Flow visualization; Dynamic pressure measurement; Dynamic loads; Secondary/unsteady flow; Vortices.