Design And Analysis Of A System Scheme Of Air-Precooled-Compressed Engine

It’s hard to realise taking off from Mach 0 to hypersonic because of the temperature limit of aeroplane engine.This paper proposed a scheme of Air-Precooled-Compressed Engine(APCE),which installed a precooler between the air inlet and the compressor dealing with the terrible working condition and low efficiency of aeroplane engine.First of all,this paper builded a system model of APCE and introduced the working mechanism of it.The design requirement of the component parameters and overall performance parameters were put forward.APCE works in Mach 0~5,altitude 0~25km.The mass flow in design point(Mach 5,25km)is 20kg/s.Helium was uesd as cooler and liquid hydrogen was used as fuel.Second,component models of design and performance analysis were builded incluing airinlet,precooler,compressor,turbo,combustion chamber and nozzle.Nonlinear programming was set to solve the interaction equation and working parameters of each component.The structure of component was designed in base of the model.Working performance of each component was analysied including flow principle of airinlet in different background pressure by using CFD,the influence of rotation speed and series to the compressor,the principle of the temperature of the chamber wall.And,thermodynamic cylce of the engin was analysied which proved the rationality of using helium as a cooler.Perfomance parameters at design point were analysied,including the influence of cooler mass flow and rotation speed of compressor and chamber pressure to the Isp,thrust and total effience of APCE.Finally,the off desing model was builed.A variable airinlet was designed to satisfy different mass flow demand.The compressor characteristic curve was studied.Perfomance of APCE along constant pressure trajetory was computed.It is proved that APCE can work steadly in Mach 2~5.