Study On Design And Operation Performance Of Supercritical Kerosene Turbopump

The system of scramjet with regeneration cooling and expansion cycle is an effective way to solve the long time work problem of hypersonic vehicle.According to the supercritical kerosene turbopump components of fuel supply system of scramjet with expansion cycle,the parameter sensitivity and matching characteristics were studied by using the combination methods of theoretical analysis and numerical simulation.Firstly,the scheme of the supercritical kerosene turbopump of scramjet with expansion cycle was designed.Considering the structure layout and working characteristics of scramjet,the design methods of centrifugal pump with low flow and low specific speed and single stage impact turbine with low pressure ratio were established respectively.The design parameters were calculated and the configuration parameters were obtained,according to the technical spcifications of turbopump.Secondly,the numerical simulation process and methods of supercritical kerosene turbopump were established.The performance parameters of turbopump were obtained by establishing 3D model,computing mesh generation and numerical solution,and the rationality of design was verified.The results show that the design scheme of turbopump meets the design requirements.The turbine can provide sufficient axial power for the centrifugal pump.The streamline of flow field of centrifugal pump is ideal and there is no vortex at the tongue,which can provide stable supercharging power for liquid kerosene.Then,the operation characteristics database and RBF neural network response surface model of turbopump were established by using DOE and high precision numerical simulation.Based on response surface method and parameter sensitivity analysis method,combined with the numerical simulation model,the parameter sensitivity of supercritical kerosene turbopump was deeply studied,including the interaction effect analysis,the Pareto distribution of influence of input variables on performance response and the multi-objective Pareto optimal frontier analysis etc.The main factors which affect the performance parameters of supercritical kerosene turbopump were obtained.Finally,by using the multi-objective optimization method,a matching optimization model for supercritical turbopump was established and the matching characteristics were deeply studied.The optimal matching condition was obtained at the design point of the turbopump.At the non design point,the two order polynomial response surface model of the matching characteristics of the turbine adjustable variables(inlet pressure,mass flow rate and temperature of working fluids)and the system was obtained,which provides a reference for the experimental research and matching control of the turbopump.The research results of thesis lay an important theoretical and practical foundation for further study on non-linear coupling mechanism of dynamics/thermodynamics of scramjet with expansion cycle during start-up process and development of engine integrated design and system integration technology.