Fluid-Structure Interaction Analysis of Hingeless Rotor Blades in Hover Considering Wake Effects

Aeroelastic analysis of hingeless rotor blades in hover was performed. Large deflection beam theory was applied to analyze blade motions with effects of geometric structural nonlinearity. Aerodynamic loads for aeroelastic analysis were calculated through a three-dimensional aerodynamic model which is based on the unsteady vortex lattice method. Wake geometry was described using a time-marching free-wake method. Lead-lag damping ratio and frequency were calculated to evaluate aeroelastic stability of hingeless rotor system. Numerical results of aeroelastic analysis for hingeless rotor blades were presented and compared with results based on experimental data and two-dimensional quasi-steady strip theory in which uniform inflow model was used. It was shown that wakes significantly affect the steady-state deflections and aeroelastic stability.