Design development and experimental studies of chambers of low-thrust rocket engines with regenerative cooling

The development and practical application of low-thrust rocket engines with enhanced reliability and functional performance characteristics is a promising scientific, technical, production and technological task in the creation of new-generation spacecraft and upper stages. In the process of implementing the Cooperation Agreement concluded by the State Scientific Center of the Russian Federation "M. V. Keldysh Research Center", the Siberian State University of Science and Technology named after M. F. Reshetnev, with the participation of Polychrome LLC, is conducting a complex of research and experimental work on the design, manufacture by additive 3D printing technologies and bench tests of prototypes of low-thrust rocket engines powered by gaseous fuels with a regenerative chamber cooling system. At this stage of the joint work, two small thrust engine chambers were selected as the object of research. These chambers were manufactured using the ASTRA 420 3D printer from the heat-resistant alloy Inconel 718 in the form of monoblock products with meridional (longitudinal) and helical (spiral) cooling channels. The thermodynamic and gas-dynamic calculations, as well as the calculation of the regenerative cooling of the chambers using methane gas, were performed using the results of experimental and analytical studies conducted by the Keldysh Research Center. The article describes the sequence of development and optimization of additive printing technology for cameras, which ensures the required product quality. The results of bench and experimental versions of two chambers with the same configuration of mixing heads and different channel orientations of the cooling system are presented in an expanded volume. When analyzing the energy and thermal parameters of the chambers obtained during fire tests, the operability of experimental designs was demonstrated, confirming the prospects of the selected technical solutions. The principal possibility of manufacturing low-thrust rocket engines using additive technology of selective laser melting from a heat-resistant alloy is shown.