Aiding take-off and reducing civil aircraft weight using the electromagnetic catapult

Abstract

The engine size of modern aircraft is principally determined by take-off conditions, since initial acceleration requires the maximum engine power. An Electromagnetic Launch (EML) system could provide some or all of the energy required during the take-off phase of the flight so that the engine power requirement and fuel use could be significantly reduced. EML also has the potential of reducing the required runway length by increasing aircraft acceleration. Expensive airport extensions to face constant air traffic growth might then be avoided by allowing large aircraft to operate from short runways at small airports. The proposed system has positive impacts on total aircraft noise and exhaust emissions near airports and improves overall aircraft efficiency through reducing engine design constraints. So far, EML for aircraft has been adopted only for military applications to replace steam catapults on the deck of aircraft carriers. This thesis considers the feasibility of different technologies for EML systems to assist civil aircraft takeoff. The research develops, models, designs and compares three possible linear motor topologies which may be used to propel an A320-200 sized aircraft up to the take-off speed. The theories exploited to design the motors are thoroughly explained while the comparison of the performance is made on results from both analytical and finite element analysis (FEA). The work is validated using a small experimental setup to launch a UAV weighing 4.5 kg. The electromagnetic analysis developed for civil aircraft launchers has been employed to size the scaled down motors and the methods proposed to design all the other components of the test rig are also presented