Numerical Investigation on the Aeromechanical Behavior in Forward Flight of a Helicopter Blade with Integrated Smart Morphing Actuator

This paper deals with a smart device aimed to give an anhedral shape to the blade tip region with the scope of reducing BVI which may cause reduced helicopter performance in terms of noise and vibrations. The blade tip morphing is obtained through the joint action of a magneto-rheological-fluid based (MRF) device, a shape memory alloy ribbon based (SMA) device and a set of concentrated masses properly distributed spanwise. The inclusion of this smart device (particularly the concentrated masses) modifies the aeromechanical behavior of the rotor and may be detrimental in terms of hub load levels, pitch control effectiveness and aeroelastic stability. Following a previous work that examined the smart actuated rotor in hovering conditions, here the numerical investigation focuses on the aeromechanical effects of the inclusion of the smart device in a four-bladed helicopter rotor in forward flight, when blade morphing is not needed. The aim of this analysis is to assess the compatibility of the presence of the smart system with the requested aeromechanical performance of the rotor, and thus the feasibility of its application on helicopters.