Research On The Key Technology Of Matching Of Near Space Super-high Pressure Ratio Turbocharging System

The super-high pressure ratio turbocharging system is the key to develop the power system of unmanned aerial vehicles(UAVs)in near space.Due to the charging limit of a single-stage compressor,it’s necessary to adopt a multi-stage turbocharging system to achieve the super-high pressure ratio charging target.It is of great significance for China’s national defense security to develop the multi-stage turbocharging system to meet the flight demand of UAV in the near space,and the matching technology is the key.Based on the theory and simulation method,this paper studies the matching technology of the super-high pressure ratio turbocharging system in the near space,and completes the research and development of the prototype of the super-high pressure ratio turbocharging power system in the near space of TS145.The system has complete independent knowledge property.For two-stage turbocharging system interstage matching research,in this paper,through theoretical analysis,on the basis of near space power system design requirements,the system total pressure should be more than 27 and the two-stage turbocharger structure is applied.Based on this,research on the high and low level of the compressor interstage matching with two-stage compressor minimum total power consumption for the principle,both air intake system design rationality of the rest of the components,finally selected high and low pressure level compressor pressure ratio of 4.5 and 6 respectively.On this basis,according to the matching principle between the compressor and the turbine,the key performance parameters of the high-low pressure turbine are further determined to complete the stage matching research of the two-stage turbocharging system.For the matching research between the two-stage supercharging system and the engine,this paper firstly built a joint simulation platform of single-stage supercharging system and engine by using GT-Power simulation software,and calibrated the singlestage supercharging platform through experimental data.On this basis,the joint simulation platform,build the two-stage turbocharger and engine control and join the supercharging system and engine matching the key modules,namely single bypass valve control module to implement the pressurization system within the full flight condition and engine power matching,finally get 0-20 km bypass valve control law,complete the turbocharging system and engine interstage matching research.For the efficient design of key components,this paper studies the influence of the special ratio of super-high pressure in near space on the design of compressor and turbine.The performance modification and optimization design method of centrifugal compressor at low Reynolds number were proposed to improve the compressor performance,and the optimal turbine inlet layout structure to make full use of the engine pulse exhaust energy was proposed to optimize the turbine performance.Finally,the prototype of TS145 near space super-high pressure ratio turbocharged internal combustion engine is introduced.In order to adapt to the low-temperature and low-pressure environment in the adjacent space,the engine body was modified to adapt to the high altitude.The prototype production of various parts of the system was completed and the prototype development of the power system was finally completed.