Aerodynamics and vibration analysis of a helicopter rotor blade

A computational model is developed to obtain a helicopter rotor blade's vibration characteristics and aerodynamic behavior. A mathematical model of the wake is also developed, consisting of fundamental wake geometry. A Bo 105 helicopter rotor blade is considered for computational aerodynamic analysis. A fluid-structure interaction model of the rotor blade with surrounding air is developed, where the finite element model of the blade is coupled with the computational fluid dynamics model of the surrounding air. The fluid-structure interaction model analyzes aerodynamic coefficients, velocity profiles, and pressure profiles. The resonance frequencies and mode shapes are also obtained by the computational method. A small-scale model of the rotor blade is manufactured, and experimental analysis of similar contemplation is conducted to validate the numerical results. Wind tunnel and vibration testing arrangements are used for the experimental validation of the aerodynamic and vibration characteristics, respectively. The wake and vortex analysis showed that the swirl velocity is minimum, and the axial velocity is maximum at the vortex center. The axial velocity decreases, and swirl velocity increases with increasing the distance from the vortex center to the core radius. Finally, an application of experimentally validated computational methodology for helicopter rotor blade to evaluate aerodynamic characteristics in a fluid-structure interaction environment along with the characterization of resonance properties is outlined where the results follow an expected pattern.