Aeromechanics modelling of tiltrotor aircraft

Abstract

A numerical investigation into the influence of different aerodynamic interaction models on the trim behaviour of tiltrotor aircraft was undertaken. The study simulated the entire conversion corridor and compared a baseline case, with no interaction accounted for, with simulations that included different interaction models: rotor-induced download on the wing; wing downwash at the tailplane; and the rotor wake effect at the tailplane. The entire conversion corridor was simulated using a reduced-order blade element/ strip theory framework. The influence of the interactions models was compared for the trimmed pitch attitude and control stick position. The most important interaction to account for was the wing downwash at the tailplane. This interaction was found to have a pronounced effect on the trim state at all operating points and in_uenced the predicted conversion corridor boundaries.