Design And Optimization For The Air Inlet System Of The Full Speed Precooled Engine

The full speed precooling engine is a new type of combined cycle engine,which can work in a wide range of Mach numbers.It is one of the ideal power schemes for hypersonic vehicles.In this paper,the air inlet system of full speed precooled engine is taken as the research object,including the scheme design of air inlet system,the aerodynamic and structural optimization design of precooled compressor,and the scheme design of principle prototype test-bed.In the aspect of inlet system design,the coupling design of inlet,precooler and compressor is put forward.The scheme realizes the integration of two aspects.One is to design the isolator and the precooler in an integrated way.The torsional precooling section with "petal" cross-section is adopted to realize the coupling of precooling and rectifying function,so that the precooling section can provide high-quality flow for the compressor while cooling the air flow.The second is to integrate the stator vane and heat exchanger,and put forward the scheme of intercooling compressor to reduce the heat load of precooler and improve the thermodynamic cycle of compressor.The above design is expected to reduce the mass of the engine and achieve the performance matching among the components of the inlet system.In the aspect of precooling compressor optimization design,the aerodynamic design of two-stage axial flow and one-stage centrifugal combined compressor with high pressure ratio and small flow was carried out,and the performance evaluation and optimization design of Intercooled compressor were completed.The results show that the combined compressor has better performance under different conditions,which meets the requirements of the design target.The intercooling scheme of tandem stators can further improve the comprehensive performance of the compressor.In the design of the principle prototype experimental facility,the system scheme design,structural design,strength and vibration analysis were carried out.At the same time,the oil system,measurement and control system were designed and analyzed.