Exploration On The Design Scheme Of Hydrocarbon Pre-cooling Engine Inlet With Wide Operation Range

With the development of the air-breathing hypersonic propulsion technology,various combined cycle engine concepts capable of achieving from the ground to hypersonic flight are increasingly valued by research institutions in various countries.One type of SABRE engine with pre-cooling technology is particularly striking.In order to meet the needs of the overall scheme demonstration of a new type of pre-cooling combined engine,a research on a wide-range inlet port adjustment scheme was carried out to match it.The axisymmetric adjustable inlet of SABRE engine was reached.The thesis explored and designed a variety of adjustment schemes,and gradually formed an axisymmetric two-channel inlet with translational splitter that can meet the requirements of the overall scheme of the new pre-cooling engine through numerical simulation research.Secondly,a study on the influence of key design parameters on the axisymmetric two-channel inlet scheme was carried out,including the initial half cone angle,the location of the leading edge of the manifold,the initial angle of the leading edge inside and outside the manifold,and lip angle,and a design scheme that can meet the overall performance requirements of the engine is finally formed.The overall performance and flow characteristics of the scheme under typical operating conditions are numerically simulated.The results show that the influence of the initial half cone angle is very important.Compared with the inlet with an initial half cone angle of 20°,the inlet with an initial half cone angle of 13 ° has its advantages,the critical total pressure recovery of Ma6 in ramjet and turbojet channel increase by 16% and 14% respectively,and the maximum windward area decreased by 12.2%,but the center cone and splitter moving distances are increased by 84% and 91% respectively;the front edge position of the shunt plate and the initial angle inside and outside affect the flow distribution and flow channel matching of the two channels;by moving the center cone and the splitter,the design scheme provided in this article can meet the requirements of the two channels of flow distribution of the turbine and stamping,and achieve the matching adjustment of the compression of the two channels to meet the working requirements of the engine.At the end of the thesis,the design scheme of adjustable inlets considering engineering application is designed,and three structural implementation schemes are compared and analyzed.The scheme of fixed center cone and translation of lip mask can reduce the adjustment distance of the manifold by 86% on the premise of unchanged overall performance,which has good engineering realization.