Use of single crystal and soft piezoceramics for alleviation of flow separation induced vibration in a smart helicopter rotor

Dynamic stall and flow separation induced vibration alleviation is investigated using single crystal and soft piezoceramic-induced shear actuation. PZT-5H performs well to reduce vibration at cruise speed (about 50%) but fails to achieve a substantial vibration reduction (about 20%) at high speed forward flight because dynamic stall and flow separation require a larger stroke for vibration reduction. $PZN-8\%PT{\langle}111{\rangle}$-induced shear actuation is found to generate a larger stroke and eventually a higher vibration reduction (about 60–70%) at both cruise and high speed flight. It is observed that the controller performs satisfactorily up to a noise level of 20% in the sensed data. Optimum placement of actuators along the span, as well as the eventualities of actuator failure and degradation are also addressed.

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