Flight dynamics of highly flexible solar-powered UAV based on geometrically nonlinear intrinsic beam

In order to obtain a convenient and precise method for the flight dynamics analysis of highly flexible solar-powered UAV, a geometrically nonlinear intrinsic beam model is introduced, it is employed to trim the UAV, and it is the base of the linearization of the flight dynamics and structure dynamics equations of motion. Proposed aerodynamics model is based on the Theodorsen unsteady aerodynamics model, it provides the Aerodynamics derivatives in every wing sections, their accumulation along the wing result in the derivatives of total UAV, and the aerodyanmics moment can be derived also by the applied arm of force. lifting-line theory is applied to accomplish the 3D aerodynamics effect correction. Base on these modeling and linearization efforts, four models are selected for comparison. The results show that, geometrically nonlinear equation of motion with 3D aeroelastics model is the only one which is able to accurately estimate the trimming and longitudinal flight dynamics behaviors, and the deformed model is quite accurate for lat-dir flight dynamics analysis.