Chugging Instability of H2O2 Monopropellant Thrusters with Reactor Aspect Ratio and Pressures

Abstract

Among the three types of instabilities, the low-frequency instability (chugging instability) was experimentally investigated with respect to the chamber pressure and aspect ratio (L/D) of catalytic reactors in a monopropellant thruster. Three H2O2 thrusters were used, and two parameters were found to be the dominant factors that generated a chugging instability of the order of several tens of hertz. A high chamber pressure and low L/D values (low pressure drop across the catalyst bed) were preferable for reducing pressure oscillation inside the reaction chamber. In addition, it was found that these two parameters were not independent but coupled; therefore, the point where chugging instability occurred varied slightly depending on the interaction between these parameters.