Experimental characterization of surface integrated electroaerodynamic thrusters

Abstract

Electroaerodynamic propulsion is a type of electric propulsion system for aerial vehicles that is potentially nearly silent. Following the first flight test of a demonstrator vehicle using this technology an area identified for improving the vehicle's performance was drag reduction of the thrusters. A proposed method for achieving this is integrating the thrusters into the surface of the vehicle to reduce the number of external bodies in freestream flow and in turn reduce drag. This thesis presents work done to experimentally characterize this specific thruster architecture and quantify how the performance of the proposed system changes with different surface materials, thruster geometries, and input voltages. Non-dimensional parameters were developed and used to guide the analysis and experimental design. From these parameters, a non-dimensional performance parameter measuring the trade-off between thrust and thrust per unit power was developed. During the experimental work this parameter was varied against a non-dimensional voltage resulting in linear relationships for both non-surface integrated and surface integrated thrusters, suggesting this parameter is important for characterizing future thruster architectures. Additional experiments found increases in the inception voltage, up to 15 kV, for surface integrated thrusters in comparison to the previous generation thruster with the same gap spacing suggesting surface charge build up modifies the electric field between the electrodes. Increasing the distance between the emitter and material surface did not reduce this effect implying this dimension does not influence the inception voltage over the range tested.