Theoretical and Experimental Investigations on the Effect of Overlap and Offset on the Design of a Novel Quadrotor Configuration, VOOPS

The theoretical and experimental investigations of a novel configuration for a Vertical Take Off and Landing (VTOL) quadrotor system with a Vertically Offset Overlapped Propulsion System (VOOPS) is presented in this paper. The objective of the VOOPS concept is to improve the load carrying capability of the VTOL system without any increase in the footprint or reduction in endurance. This has been accomplished by overlapping the propeller blades with a vertical offset such that they don't intersect. This way VOOPS can accommodate a larger propeller size without increase in footprint. The aerodynamics of the overlap and offset on the quadrotor performance has been analyzed using Blade Element and Momentum Theory (BEMT) and a methodology has been proposed to find their effects on thrust, drag, and power. The important design constraints for VOOPS are offset and overlap of the propellers, whose limits are evaluated using the blade-bending profile and the geometry of the propeller, respectively. The mathematical model and the design of a VOOPS quadrotor system is also presented. A quadrotor with VOOPS configuration has been designed and experimental studies have shown that the theoretical results obtained are in good agreement with the experiments. The practical implementation of VOOPS configuration and the consequences of the design changes are also presented.