Structural Design Of Helicopter Rotors With Gurney Flaps

Improving helicopter flight performance is a hot research topic on helicopter.Gurney flaps have great potential in improving helicopter performance and reducing rotor vibration and noise.This work focuses on the structural design of rotor blades with a gurney flap driven by a piezoelectric cantilever beam.First,the analytical expression of the deflection displacement is derived by Euler-Bernoulli beam model and the classical laminated plate theory,respectively.The effectiveness of the proposed method is verified by comparing the results generated by these models with the data in a reference.The finite element method is used to investigate the influence of structural parameters on the deflection displacement.The results show that reducing the thickness of the piezoelectric sheets and placing them near the root of the beam can obtain relatively larger displacement.Second,the dynamic characteristics of the piezoelectric cantilever beam is analyzed.The influence of structural parameters on each mode frequency and amplitude at the resonance is studied.The relationship between the force and driving voltage with the same deflection displacement and the displacement response curve with the excitation by different frequency is obtained.The static strength of the beam in the centrifugal field is investigated and the stress can satisfy the strength requirement.Third,the integrated design of the drive mechanism and the Gurney flap is conducted.The research specifically focuses on the position and placement of the drive mechanism,the Gurney flap and various parts in the blade.Finally,a three-dimensional model of the blade with a Gurney flap is built and the experimental scheme of exploring the driving performance of the piezoelectric cantilever beam and the deflection displacement of Gurney flaps is given.