Aeromechanics of an Optimized, Actively-Morphing Rotor System
Final progress rept. 1 Oct 2008-1 Oct 2011
MARYLAND UNIV COLLEGE PARK ALFRED GESSOW ROTORCRAFT CENTER
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The objective of this research was to investigate the potential of rotor morphing to improve the performance of baseline helicopter configurations. The morphing parameters that have been considered in this report are variable rotor speed and variable rotor radius. Both of these parameters are considered in steady state only, so that transients that would be introduced during blade morphing are not considered. Additional morphing concepts including variable twist, chord, camber and tip shape could not be completed due to time constraints. The comprehensive rotorcraft analysis code, UMARC, was modified to accommodate steady variations. The structural model is a full, non-linear, finite element analysis formulation. Each blade is modeled as an articulated, flexible beam with coincident flap and lag hinges. The aerodynamic model is a Weissinger-L type lifting-surface model coupled with 2D airfoil tables, unsteady effects are captured using the Leishman-Beddoes model, and a time accurate free wake model, captures the wake.