Analytical Flight Dynamic Model Development for eVTOL Aircraft

Nhan Nguyen; Benjamin Webb

NASA NTRS · 20240016179

Analytical Flight Dynamic Model Development for eVTOL Aircraft

Abstract

This paper presents an analytical flight dynamic model development method for a multi- rotor eVTOL aircraft in hover and transition flight. The method captures the analytical stability and control sensitivities of rotor unsteady aerodynamic loads about a trim solution generated by a rotorcraft aeromechanics comprehensive analysis tool. The rotor aerody- namic forces include circulatory and non-circulatory components to account for unsteady aerodynamics. The circulatory forces are corrected for unsteady aerodynamics using the time-domain approximation of Theodorsen’s function. The integrated flight dynamic model includes the rigid-body aircraft flight dynamics, inflow dynamics, unsteady aerodynamics, and blade pitch and rotor actuator dynamics. Stability analyses shows that the Lift+Cruise aircraft is statically unstable in roll and yaw axes and also dynamically unstable in hover. Closed-loop feedback control is necessary for stable hover flight.

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Nhan Nguyen, Benjamin Webb. Analytical Flight Dynamic Model Development for eVTOL Aircraft. https://ntrs.nasa.gov/citations/20240016179

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