Linearized Rotorcraft Wake Model for Advanced Configurations

Linearized inflow models have been used to represent dynamic wake effects with great success for aiding control law development and flight dynamics investigations of conventional single-main rotor / tail rotor rotorcraft, but are difficult to extend to alternate configurations such as coaxial rotors, tiltrotors and compound aircraft having significant interacting wake effects. By contrast, CDI’s real-time free wake analyses can support manned flight simulation on all rotorcraft types, but are not readily used within control law development, as they are not formulated in a state-space representation as ordinary differential equations. In Phase I, CDI leveraged our CHARM free wake analysis to develop and demonstrate prototype software for extracting linearized models of rotary-wing aircraft aerodynamics for single and coaxial main rotor systems. The proposed Phase II research and development will generalize and validate the methodology for conventional and advanced rotorcraft configurations that include multiple rotors and/or lifting surfaces. A commercial software suite will be developed based on inputs from industry end-users that will provide superior flight dynamics analysis and control law development for both standard rotorcraft and future advanced configuration VTOL aircraft.