Performance Analysis, Engineering Application, Design And Evaluating Of Coaxial Tripropellant Injector

Focusing on the performance evaluating and the design of tripropellant injector, adopting the cold test rig with background pressure supply, Malvem Particle Analyzer, CCD photography system, tripropellant hot test-bed, numerical simulation software and auxiliary theoretical a nalysis, the d ischarge c haracteristic a s w ell a s a tomization p erformance o f the injector and the combustion performance as well as the mode-transition characteristic of thrust chamber are studied detailedly based on the 3 different structures of coaxial tripropellant injector, large numbers of important conclusions are gained. The design method of coaxial tripropellant injector is summarized. A parameter for evaluating the performance of the injector is presented. Gaining the empirical formula and the varying regularity of the discharge coefficient of the internal-mixing outer nozzle, as well as the discharge characteristic of the tripropellant injector; Finding the mass flux ratio of gas to liquid (i.e. ALR) is the most important parameters deciding the performance of the internal-mixing outer nozzle; Presenting the empirical formula and the varying regularity for the pressure at the mixing cavity of internal-mixing injector, which is widely suitable; Presenting the concept of Overall Discharge Characteristic (i.e. ODCH) for describing the varying regularity of the discharge characteristic of internal-mixing injector, concluding the empirical formula and the varying regularity of Overall Discharge Coefficient (i.e. ODCO) for gas and liquid; Presenting the concept of Operating Range, concluding the varying regularity of Operating Range; Discovering the two competitive atomization process, and 3 main flow shape of gas-liquid mixture; As to the SMD of outer nozzle, offering the empirical deciding by ALR and gaining the affecting rule of geometry variance; As to the tripropellant LRE, the pre-mixing injector producing the worse performance including combustion performance and the mode-transition one, while internal-mixing injector give the better combustion performance, external-mixing the better performance of both combustion and mode-transition; As to the combustion efficiency of tripropellant LRE, the augment of coefficient of oxidizer-remainder will lead to the increase of efficiency while the augment of hydrogen percent does not improve the efficiency; Presenting the evaluating parameters of mode-transition characteristic for the first time, and gaining the variance regularity of that along with the operating parametersof rocket engine; Presenting the "Number of Overall Performance" for injector as well as providing the calculation method. Summarizing the design method of tripropellant injector.