Calculation of the parameters and characteristics of a rotating lunar jet penetrator

The purpose of the work is to determine the parameters of the internal ballistics of a solid propellant jet engine mounted on a jet penetrator entering the ground at a high rotation speed around its own axis. Research methods: to determine the pressure in the chamber of a rotating engine, the known equations for the balance of gas inflow and consumption are usually used, as in the case of a non-rotating solid propellant jet engine. The difference between the internal ballistics of a rotating solid propellant jet engine is that the effect of rotation on the operating process is taken into account by the coefficient of gas flow from the chamber of the rotating engine; a change in the rate of erosive combustion of solid propellant during rotation of a solid propellant jet engine; heat loss coefficient. Results: it was found that the parameters of the internal ballistics of rotating jet engines of solid propellant are mainly influenced by the coefficient of gas flow from the chamber of the rotating engine; effect of erosive combustion of solid propellant and change in heat loss coefficient. The main calculated dependencies for determining the pressure in the combustion chamber of a rotating solid propellant engine are presented for periods when the pressure reaches a stationary mode of operation of the engine, operation of the engine in a stationary mode and during the period of free flow of gases from the chamber of a solid propellant jet engine. A method for selecting the linear and angular dimensions of a rotating engine nozzle is presented. An estimate of the thrust force for a single nozzle rotating solid propellant jet engine is given. It has been established that the magnitude of the thrust force of rotating engines (under other identical conditions in the combustion chamber) is 1.1–1.36 times less than that of non-rotating solid propellant jet engines. The experiments carried out showed a decrease in the degree of swirl of the gas flow of rotating solid propellant engines with an increase in the number of propellant pellets in the engine charge. Conclusion: the results presented in the article can be useful for scientists, graduate students and engineers involved in the creation and operation of aviation and rocket and space technology, and can also be useful for students of technical universities studying in relevant specialties.