Design and Testing of a Hydrogen Peroxide Bipropellant Thruster

摘要

As the world is trying to shift toward a more environmental friendly economy the propulsion community is looking toward green propellants to pursue this goal. Although the performance of these propellants may be lower compared to the most widely used toxic propellants (i.e. hydrazines), the demanding safety restrictions and the increasing concern for human health make them a cost-effective alternative solution. A 450 N bipropellant liquid engine based on highly stabilized hydrogen peroxide and kerosene is currently under study at the University of Padova. In this paper, the first developing phase, focused on the combustion chamber investigation, is reported. Unlike other liquid motors based on these propellants the one presented here features a cooling solution for the thrust chamber characterized by a double co-spinning counter-flowing vortex flow. It is well known that a swirled flow improves mixing and residence time thus enhancing the combustion efficiency. Moreover, this particular flowfield allows the flame to be trapped in the inner vortex while the outer one composed only by the oxidizer act as a shield that extract heat from the chamber walls. An experimental investigation has been made to characterize the engine performance as function of the geometrical parameters of the combustion chamber since no data, as far as the authors know, have been found in the literature for the selected propellants combination and this particular flowfield. Two fire test campaigns have been carried out. The first one has been focused on the size of the thrust chamber and the second one on the influence of a secondary oxidizer injection. The cooling solution has been confirmed and demonstrated for both the engine configurations. The higher specific impulse efficiency obtained is 96％ with an oxidizer split ratio of 25%.