Study On Combustion Characteristic Of Gas Oxygen/gas Methane Small Thrust Pintle Engine

The small thrust pintle engine is taken as the research object for the study,to investigate the effects of momentum ratio,block ratio,hole type and characteristic length on the combustion performance of the pintle engine,the method of experiment and simulation is adopted.Firstly,the flow characteristics and combustion characteristics of the pintle engine were studied experimentally with different mixing ratios.The following conclusions are drawn by analyzing the data obtained in the combustion test,such as flow rate,pressure and temperature,as the ignition energy increases,the success rate of ignition increases,and the combustion efficiency increases with mixture ratio increasing.Then,the effects of the momentum ratio on the flow field structure and combustion process of the pintle engine are studied through the simulation.The results show that the temperature distribution in the central region of the combustion chamber is distributed in banded and stratified along the radial direction,and at the region where closes to the wall surface of pintle engine,the temperature distribution exhibits a gear shape distribution,which changes between the high and low along the circumferential direction.As the momentum ratio increases,localized combustion of the propellant in the combustion chamber is enhanced,resulting in increased combustion efficiency.Finally,a method of simulation was adopted to study the effects of the hole type,the blocking ratio and the characteristic length on the flow field structure and the combustion process.The results show that the combustion efficiency is higher in the case of rectangular holes;in a certain range,as the blocking ratio increases,the hole spacing of the injector decreases,and the mixture of jet weakens,so the combustion efficiency is lower;As the characteristic length of the pintle engine increases,the residence time of the propellant in the combustion chamber increases,and the combustion reaction becomes more sufficient,and the combustion efficiency also increases.