Matsoukas, G. and Ahmed, N., "Experimental Investigation of Asymmetrical Capacitors for Electric Propulsion," SAE Technical Paper 2014-01-2221, 2014, doi:10.4271/2014-01-2221.
Investigation into electric propulsion continues to be an area of hopeful research since the pioneering age of aviation. However, more recent global awareness of carbon emissions on the planet and the desire to create more efficient systems has reinvigorated new life into the field. Experimental studies on electric propulsion by virtue of asymmetrical electrodes, on a micro scale, have yielded potentially superior efficiency ratings when compared to currently adopted methods. The observed effect is that asymmetrical electrodes which are subjected to high voltage and are separated by a fluid dielectric medium experience thrust towards the smaller electrode.This method of propulsion is unique and possesses several features that differentiate it from conventional methods of propulsion. One major benefit of this phenomenon is that the electrical energy is directly converted into a mechanical force without the requirement of any moving components. Such a method of would only require a high voltage power supply unit drawing relatively low current. The implications of this include increased travel time, improved maneuverability and improved stealth characteristics. Craft of this essence would eliminate both acoustic and heat signatures due to the absence of exhaust heat and noise like conventional propulsion systems.To date, the characteristics of the thrust produced on the asymmetrical electrodes are not entirely understood. In the context of increasing the ability of this technology, an experimental program at the University of New South Wales Aerodynamics Laboratory is under-way which investigates model asymmetrical electrodes charged with voltages ranging from 0-30 kV. A series of characteristic experiments are conducted aiming to gain a deeper understanding of the phenomenon which include varying emitter electrode diameter, the inter-electrode separation and collector electrode radius of curvature. In addition, the electrodes were influenced by a permanent magnetic field placed in various positions aiming to increase the thrust performance of the system. As a result, it is found that both the geometry of the electrodes and magnetic fields greatly affect the thrust on the asymmetrical capacitor.