Development and Validation of a Semi-Empirical Approach to Modeling of the Blade Torsional Dynamics for Active Rotors

Active rotor blades usually operate in an environment with high pitching moment and relatively low torsional stiffness. The blade torsional dynamics becomes a dominant physical attribute and is no longer negligible for flight simulation. A semi-empirical approach was developed to model the effective torsional dynamics in a rigid blade model. The purpose is to augment the rigid blade model fidelity to an adequate level for active rotor modeling without sacrificing the real-time simulation capability. This new approach was used to model a full scale active rotor with trailing edge flaps and validated against results from a finite-element elastic blade model. The model was able to correlate well with a set of whirl test data.