Design and Testing of a 3D Printed Regenerative Cooled Nozzle for a Hydrogen Peroxide based Bi-Propellant Thruster

In recent decades, the technological development, like the miniaturization of electrical and mechanical components, as well as the research on new materials and manufacturing processes, is making it possible to significantly expand the capabilities in space. At the same time, aware of the impact on the environment and on human health, many research groups are focusing on the use of green propellants, even if in some cases less performing compared to the other currently employed toxic or carcinogenic substances such as hydrazine. In this context, a 3D printed regenerative cooled nozzle has been designed, developed and tested for a 450 N high-concentration hydrogen peroxide-based bi-propellant engine under study at the University of Padova. The decision to investigate this thermal control technique is related to the possibility of improving the performance of the propulsion system, although with an increase in technical complexity. In this paper, the numerical model developed to predict the cooling performance of the nozzle, the design of the hardware and its verification trough the experimental test campaign are reported. An extensive test campaign has been conceived and carried out in order to investigate step by step the sealing and the thermo-mechanical behavior of the nozzle with different thermal conditions, both in monopropellant and bipropellant mode and with axial and swirled flows.