Numerical and Experimental Study of Active Flutter Suppression With Piezoelectric Device for Transonic Cascade

Possibility of active suppression for transonic cascade flutter with piezoelectric device was studied both numerically and experimentally. In the numerical study, a previously proposed control method in which the blade trailing edges were actively oscillated was analyzed in detail toward realistic application by a developed numerical method with flow-structure coupling. From the results, the effect of the control was confirmed, and the suppression was revealed to come from the appropriate change in the oscillatory behavior of the passage shock. Experimental study was conducted in linear cascade wind tunnel under transonic flow condition to verify that the method realized substantial effect on stability of the blade oscillation. Unsteady aerodynamic forces induced by the active oscillation of a blade on which piezoelectric devices were glued were measured and superposed with the unsteady induced force causing flutter instability. The results showed a distinctive stabilization effect of flutter suppression in the case with appropriate phase difference between original blade vibration and the active oscillation of the piezoelectric device. The active oscillation was, however, found to generate destabilization effect if the phase was inappropriate.