Helicopter Rotor Load Prediction Using a Geometrically Exact Beam with Multicomponent Model

摘要

In this paper, an accurate structural dynamic analysis was developed for a helicopter rotor systemincluding rotorncontrol components, which was coupled to various aerodynamic and wake models in order to predict an aeroelasticnresponse and the loads acting on the rotor. Its blade analysis was based on an intrinsic formulation ofmoving beamsnimplemented in the time domain. The rotor control system was modeled as a combination of rigid and elasticncomponents. A multicomponent analysis was then developed by coupling the beam finite element model with thenrotor control system model to obtain a complete rotor-blade/control-system aeroelastic analysis. The rotor bladenanalysis was in good agreement and validated by comparing with DYMORE. Numerical results were obtained for anfour-bladed, small-scale, articulated rotor rotating in vacuum and in a wind tunnel to simulate forward-flightnconditions and its aerodynamic effects. The complete rotor-blade/control-system model was loosely coupled withnvarious inflow and wake models in order to simulate both hover and forward-flight conditions. The resulting rotornblade response and pitch link loads are in good agreementwith those predicted byCAMRADII.The present analysisnfeatures bothmodel compactness and robustness in its solution procedurewhile capturing the sophisticated behaviornof individual rotor components. The analysis is expected to be part of a framework useful in the preliminary designnphase for helicopters.