Aerodynamic and LPV Modeling of a Distributed Propulsion Morphing Wing Aircraft

Abstract

Hybrid-electric, unconventional aircraft solutions can possibly be the solutions for the ambitious emission reduction targets set by regulators, based on society's demands. One such disruptive solution is a morphing wing cargo UAV, with distributed propulsion. This paper investigates the aerodynamics, flight dynamics and control of a scaled down technology demonstrator UAV, built to validate the feasibility of the morphing wing concept. Several types of analyses are run to gain knowledge on the performance, stability and control properties of the aircraft. The flight mechanical effects of the distributed propulsion system are taken into account based on the integral momentum theorem. The increased flow speed behind propellers increases the local lift forces. Therefore, the distributed propulsion can be used to control the roll, pitch and yaw motion of the morphing wing aircraft. The nonlinear 6 degrees of freedom, distributed propulsion aircraft model is constructed utilizing the stability and control derivatives obtained from the aerodynamic analysis. Grid and Tensor Product (TP) type linear parameter-varying (LPV) models of the morphing wing aircraft are generated via Jacobian linearization and TP model transformation. The LPV models capture the parameter varying dynamics arising from the airspeed, morphing wing and payload weight variations. Gain scheduled lateral and longitudinal baseline controllers are synthesized using the grid-based LPV model of the aircraft.