The Coupled Modeling And Characteristics Analisis Of TBCC Propulsion System And Aerocraft

To achieve low-speed take-off and accelerate to high supersonic,a combined propulsion system must be used.The TBCC propulsion system is an ideal choice which segments the high specific impulse of the turbine engine in low Mach and the ramjet engine in high Mach.And there is a strong coupling between the propulsion system and the aircraft,which can easily cause the failure of the mission.So an aircraft that can match the propulsion system is also an important part of achieving a stable flight.In this paper,the airframe/propulsion integration system using TBCC engine is studied,and the different characteristics of TBCC propulsion system and its independent operation and coupling are analyzed.Firstly,considering the flow distribution problem in the transition process of the TBCC propulsion system,a dual-channel inlet was quoted.Through the swing of splitter,the process of the channel area changes and the flow distribution was simulated.The whole working condition was calculated.Three modes,such as pure turbine mode,transfer mode,pure ramjet mode and multi angles,such as flow condition,Mach number,shock angle,mass flow rate,flow coefficient,total pressure recovery of the combined inlet were analyzed.Which provides the basic data for the building of the intake system.Secondly,according to the engine thermal calculation process,the TBCC engine model was built on the Matlab/Simulink platform,and the range Mach number transfer method was used,and the transition stage is defined as Ma2.0~2.4.Then,based on the principle that the total thrust is constant in the transfer mode,the control law of the turbine and ramjet was designed.And three kinds of control laws after transition were given and simulated.The dynamic characteristic parameters of engine in different control laws,such as the thrust,shock position,total temperature and Mach number of combustion outlet were emphatically analyzed.Thirdly,a wave-rider vehicle model was establishment and a controller which can work stably was also designed.Different trust,different dynamic pressure and flight path were simulated in the aircraft level.And the flight behavior was analyzed from three aspects of flight attitude,flight state and flight aerodynamic force.Finally,the airframe/propulsion integration system based on TBCC engine was formed,and an acceleration closed-loop control system was also designed.Through the analysis of the simulation results under different control laws,the forming process of the integrated coupling characteristic was explained,the reasons that may cause the instability of the model were analyzed and explained through the design of different conditions.