Validation of methods for increasing the efficiency of detonation jet engines
Authors: Stoliarchuk Vitalii 
Published: August 2024

A fundamentally new direction in the development of rocket and space technology is the introduction of jet engines operating on the detonation principle of energy conversion in the working body. The use of detonation fuel combustion makes it possible to increase the thermodynamic efficiency of the engine and the thermodynamic efficiency of fuel combustion. Detonation is a hydrodynamic wave process involving the propagation of an exothermic reaction zone in a substance at supersonic speed. The detonation wave is the main shock wave behind the front of which a chemical reaction is continuously initiated by heating during adiabatic compression. A feature of this process is the large pressure drop before the detonation wave and in the induction zone, where the reaction occurs. The completeness of the combustion of the fuel mixture in the chambers in the detonation mode can be significantly increased by the occurrence of large pressure and velocity gradients. The problem of increasing the efficiency of jet detonation engines should be solved in the complex of structural synthesis using the accumulated knowledge about jet engines with deflagration fuel combustion. The purpose of the work is to obtain the results of studies of the defining characteristics: the development of mathematical models of the kinetics of gas-dynamic and thermal processes in the detonation combustion chamber with aerodynamic regulation; taking into account the composition and properties of the gas in the working environment of the chamber; modeling of work processes in the flow part of the engine; study of the mechanism of self-oscillations in the chamber based on kinematic patterns of gas movement; development of methods of experimental measurements of detonation flows for verification of calculation models; and improvement of the engineering methodology for calculating detonation combustion chambers with aerodynamic regulation of a detonation jet engine for a given power. Based on the results of theoretical and experimental studies, an engineering method for chamber calculation is proposed. Mathematical models of gas-dynamic and thermal processes in a detonation combustion chamber with aerodynamic regulation, which take into account the ratio of air to fuel consumption, are proposed, and allow determining the properties and composition of combustion products. Calculated equations were obtained for determining the frequency of oscillations in the detonation combustion chamber taking into account aerodynamic regulation. A method was developed for calculating the kinetics of gas dynamic and thermal processes in the detonation combustion chamber depending on the coefficient of excess air with aerodynamic regulation. Comparing the changes in the position of the flame front under the conditions of different injection distances, it was determined that for the same injection scheme but different cavity configurations, the position of the flame front has the same tendency as the change in the equivalence coefficients, which is related to the power igniter discharge and the medium of the flow field inside the cavity. Experimental studies on the characteristics of detonation engines and their implementation are relevant for the introduction of the latest innovative technologies in the rocket and space industry in Ukraine.