Performance Mathematic Model And Operation Characteristic Analysis For Turbine Based Combined Cycle Engine

For it's excellent performance, Turbine-Based-Combined-Cycle(TBCC) should be the most competitive propulsion system for the future Hypersonic Flight Vehicle. TBCC system includes some pivotal ingredient, for example, scheme selection and model design of Vehicle, engine design, all-body and components performance analysis, in all of which, the engine modeling play an important role.Based on quasi 1-D flow equation, the relationship between airdynamical parameters and engine performance index was found. With this precondition, the performance analysis model was estabilished based on the components maps, which reflect the property of components.In this paper, a calculated tool has been created, which was written in C++. The program can analyze many configurations including a turbojet, afterburning turbojet, ramjet and TBCC engine. During the simulation, the effect of the radius of the leading edge on the flow fields and the performance of the inlet were investigated, meanwhile, the effects of the inlet design by the bluntness were pointed, and some ways were provided to solve the problem. Using this program, the main modes of the TBCC has been calculated. The results told that the program was feasible.Based on the inlet/engine matching, inlet performance analysis model was established, from which, the characteristic of inlet was analyzed. Similarly, the nozzle analysis model was also realized, with the capability of simulating integration of nozzle/vehicle-afterbody.In view of surge in combustor would bring ruinous effect to the ramjet, influence which was led from the burner's pressure has been discussed. From the result, a limitative range of the pressure's change is less than±10%.At the end of this paper, property of the transition state has been analyzed. In this state, the performance of engine would slack up at the point of turbojet shutdown quickly. Both improving the temperature after the ramjet combustor and extending the operation range of turbojet, could meliorate the performance of propulsion system at the transition state.