Local Power Exchange Between a Pitching and Plunging Airfoil and the Transonic Flow

Abstract

The objective of this report is to gain a better understanding of the impact of the local aerodynamics about an airfoil on limit-cycle oscillations. Here the local power exchange is evaluated on the basis of measured static pressure distributions simultaneously obtained with motion data of the moving airfoil. The evaluation of the local power exchange is checked by comparison with the global power exchange obtained from the aerodynamic load coefficients. From the local power exchange over the airfoil can be concluded that the shock-wave dynamics mostly influences the amplification and the amplitude limitation of LCOs. Furthermore, possibly boundary-layer separation close to the trailing edge influences the behaviour of the aeroelastic system.