Performance Measurements on a UAV-Scale Cycloidal Rotor in Hover

This thesis discusses the optimization of a UAV-scale cycloidal rotors (or cyclorotor0 s) aerodynamic performance in hover through an extensive experimental parametric study and the development of a cyclocopter UAV. The current parametric study focused on collecting systematic time-averaged thrust and power measurements to characterize the effect of pitch kinematics and rotor geometry on the performance of a cyclorotor operating at Reynolds numbers between 100,000 and 300,000. Experiments were conducted for a range of rotational speeds across different blade pitch amplitudes for rotor configurations with varying airfoils, blade spans, chord-by-radius ratios, and number of blades. Based on the 37 unique rotor configurations, at an operating Reynolds number of 200,000, the optimal cycloidal rotor configuration had a chord-by-radius ratio of 0.66, 3 blades featuring a blade aspect ratio (span/chord) of 4 and a NACA 0020 airfoil, rotor aspect ratio (span/diameter) of 1.33 and cyclic pitch amplitude of ±40◦ and obtained a figure of merit of 0.6. The 17 lb. technology demonstrator prototype featured a dual-rotor configuration with cyclorotors featuring a novel split-blade design positioned at the front and rear of the vehicle. The vehicles rotors were designed based on the results from the parametric study. Flight performance was demonstrated through gimbal, tethered and free-flight tests