Research On The Thermal Management Method Of Ramjet And Its Combination Engine Based On The Comprehensive Utilization Of Thermal Electricity And Cooling

This research mainly focuses on the heat management of compact parallel combined engine.The main contents of the research include the thermal management requirement analysis of compact integrated combined engine,the performance comparison analysis of various schemes for thermal management of combined engine,and the coupled thermal management of engine combustor and its accessories under the strong three-dimensional spatial distribution characteristics.Characteristic analysis and optimization,research on heat management scheme of engine's comprehensive utilization of cold electricity and thermoelectricity.Firstly,the particularity of thermal management for compact integrated engine is analyzed.It is concluded that the main object of thermal management for compact integrated engine includes not only the combustion chamber wall,but also the engine cabin wall accessories,and the thermal management effect of combustion chamber wall on the thermal management effect of cabin accessories.The results have a greater impact.Therefore,combined with the operation characteristics of the compact integrated engine and the special requirements of heat management,the available cold sources of the engine under wide operating conditions and multi-mode are analyzed.At the same time,in order to evaluate the effects of different heat management schemes,the thermal structures of the combustion chamber wall with the coupled regenerative cooling and film cooling structures are established respectively.One-dimensional computational model.Secondly,according to the actual situation of the compact integrated engine,the performance evaluation and comprehensive evaluation of the fuel regenerative cooling heat management scheme and the film cooling heat management scheme are carried out respectively.Through the comparison of various schemes,it is found that the film cooling heat management scheme is suitable for the thermal management requirements of the compact integrated engine.Because of the poor control performance of combustion chamber wall temperature and ambient temperature of engine accessories,it is not suitable for heat management of compact integrated engine.Regenerative cooling heat management scheme has good control performance of ambient temperature of engine wall and engine accessories,and has the potential to be used with higher Mach number.Potential,therefore,it is more suitable for the application of compact integrated combined engine.At the same time,it is also found that the regenerative cooling heat management scheme has a great dependence on fuel flow,and the cooling flow needed in the cruising condition of engine with high Mach number is larger than the combustion flow.Then,in order to further study the thermal management performance of the regenerative cooling heat management scheme for compact integrated engine,considering that the engine,especially the engine cabin accessories,has a strong three-dimensional spatial parameter distribution characteristics,a coupling analysis of the regenerative cooling heat management scheme for the engine under the strong three-dimensional spatial distribution characteristics is established.By decoupling the calculation model,the model is divided into two processes: the regenerative cooling numerical simulation of the combustion chamber under the strong three-dimensional spatial distribution and the thermal environment numerical simulation of the engine cabin under the strong three-dimensional spatial distribution.The temperature distribution of the combustion chamber wall is used as the interface of the two processes.Through the above analysis,it is found that the regenerative cooling heat management scheme can achieve good thermal management of engine wall and engine cabin accessories under the operating conditions of Ma4,which is the upper limit of engine design.At the same time,the regenerative cooling heat management scheme can still perform better thermal management of engine under higher flight Mach number.The active cooling structure is designed for parts with high working temperature because of their special position.The performance of the active cooling structure is evaluated by three-dimensional numerical simulation.Finally,in view of the large dependence of regenerative cooling heat management scheme on fuel flow,this topic provides a solution based on the comprehensive utilization of cold electricity and thermoelectricity.That is to say,the fuel in the stamping mode combustor is refrigerated and cooled in advance by means of refrigeration and cold storage,which makes it possible to recover the surplus fuel after regeneration cooling.Aiming at the problem that the electric refrigeration cycle needs to exhaust heat from the environment,and there is a thermal barrier between the aircraft and the external environment,the scheme innovatively puts forward that the heat in the cycle should be discharged into the fuel which will be burned in the turbine mode,that is,to make full use of the fuel heat sink under low Mach number and to expand the fuel heat sink under high Mach number.Purpose of using cold source.