Helicopter forward flight prediction using geometrically exact beam model and an advanced unsteady aerodynamics

This paper presents a combination between the computational structural dynamic and aerodynamic analysis. In present computational model, geometrically exact beam formulation for the structural analysis and finite state dynamic inflow aerodynamics combined with blade element theory are used. The present beam formulation features advantages that displacements, inertial forces, and momenta can be directly extracted and solved simultaneously. Finite state dynamic inflow aerodynamics is used to predict induced inflow in forward flight. It calculates unsteady aerodynamics and will cost less computational time than the other wake models do. To combine those two analyses, a loosely coupled scheme is used. For the numerical analysis, both wind tunnel trim and free flight trim analyses are conducted. The present results are verified by comparing with those predicted by CAMRAD II.