Analysis and design of passive thermal controls applied to monopropellant thrusters

Monopropellant space thrusters exploit high pressure hot gases generated by the decomposition of the propellant. Recently, high concentration hydrogen peroxide (HTP), despite showing lower performance than other propellants, has become a promising solution in this field thanks to the reduced environmental impact and safety risks related to its handling. This dissertation discusses passive thermal control systems for HTP monopropellant thrusters. A mono-dimensional thermal model to evaluate the heat exchanges with the external environment is proposed, with particular focus on the internal transfer mechanisms between the fluid and the chamber wall. It is then calibrated employing experimental data from firing tests. The model is utilized to analyzed a real in-space application, characterized by a specific mission profile and external heat load. Based on the outcomes of the numerical analysis, a possible passive thermal control solution is presented and discussed.

Monopropellant space thrusters exploit high pressure hot gases generated by the decomposition of the propellant. Recently, high concentration hydrogen peroxide (HTP) has become a promising solution in this field thanks to the reduced safety risks in its handling and to the more environmentally friendly exhaust products. This dissertation discusses passive thermal control systems for HTP monopropellant thrusters. A mono-dimensional thermal model to evaluate the heat exchanges with the external environment is proposed, with particular focus on the internal transfer mechanisms between the fluid and the chamber wall. It is calibrated employing experimental data from firing tests. The model is utilized to analyze real in-space applications, characterized by different mission profiles and external heat loads. Based on the outcomes of the numerical analysis, possible passive thermal control solutions are presented and discussed.