Study on the effect of combustion efficiency of variable thrust rocket engines

In this paper, using methane/oxygen as the engine propellant, the single nozzle structure and the coaxial shear injection unit were used to analyse the influence of propellant flow change on the combustion chamber flow field and the influence of different factors on combustion efficiency. The results show that as the pressure of the combustion chamber increases, the concentration of the components increases, the combustion reaction speed is accelerated, and the maximum temperature of the combustion chamber increases, but the radial length of the high temperature area decreases; The pressure of the combustion chamber is proportional to the flow rate of the propellant, the flow of the propellant is reduced, the pressure of the combustion chamber is reduced as a whole, and the transportation speed of the material components in the combustion chamber is increased, which in turn reduces the maximum temperature of the combustion chamber, and ultimately leads to a decrease in combustion efficiency; In the process of continuous change of propellant flow, fuel flow, combustion chamber pressure, combustion chamber temperature and combustion chamber material composition jointly affect the combustion efficiency, but the influence of fuel flow on combustion efficiency dominates.