Analysis Of Linked Aircraft Aerodynamics And Flight Dynamics
In this research, I have analyzed different aircrafts with nonconventional wings. The analyses have included aerodynamic modeling, flight dynamics and trajectory optimization. Two different nonconventional aircrafts are analyzed, a V-shape morphing wings and a Linked UAV system. A modern adaptation of Prandtl's liftingline method is utilized to analyze the aerodynamics of both systems. This method can compute the aerodynamic forces for a system of lifting surfaces with arbitrary camber, sweep, dihedral, position and orientation. The V-shape morphing wings consist of a wing configuration that has two panels, an out-of-plane dihedral section and a horizontal section. An analysis of the aircraft turning dynamics shows that by manipulating the dihedral angles, of the V-shape wings, either by symmetric or asymmetric wing shape changes, can affect the turning capabilities of an aircraft to perform a variety of different missions depending on the importance of each of the turning performance measurements. A linked UAV concept, where individual UAVs link at high altitude, creates an aerodynamically efficient system of aircraft which has long endurance capabilities and can cruise for extended periods with significantly reduced power loads. This dissertation presents an analysis of close proximity aerodynamics and aircraft dynamics of two Linked UAVs. As the UAVs approach each other for wingtip docking there are strong aerodynamic coupling between their wings tips. An aerodynamic disturbance intensity field has been generated, utilizing both simulation and wind tunnel data, to determine a trajectory for the two UAVs to approach each other for midair docking. Finally, two optimal trajectories, a 2-D and 3-D docking trajectories are generated and compared. Dynamic wind tunnel test are performed to compare different midair wingtip docking trajectories. The results of the optimization concludes that a trajectory with a span-wise approach is more desirable since it goes through the least aerodynamic disturbances and requires less control effort to perform the midair docking maneuver.
Linked UAV; Lifting-line Method; Aircraft Dynamics
Caughey, David Alan; Hencey, Brandon M.
Ph. D., Aerospace Engineering
Doctor of Philosophy
dissertation or thesis