Propulsion Performance Analysis And Trajectory Planning Of Rocket-based Combined Cycle Powered Aircraft

The Rocket-Based Combined Cycle(RBCC)advancement is one of the earlier proposed combined propulsion methods.However,the advantages of RBCC compared with other combined propulsion methods,as well as the height of its effective work and the Mach number interval have long lacked a broad consensus.In this paper,by establishing the thrust model,planning the climbing trajectory and the simulation of specific working conditions,this paper proposes the thrust demand and feasible increase method of the flight envelope for a rocket rear-mounted RBCC engine configuration.Firstly,according to the characteristics of RBCC with high thrust requirements during the climbing process,a rocket rear-mounted combustion chamber configuration is proposed,which has the characteristics of short structural size and good thermal environment.Based on the independent stamping flow,a quasi-one-dimensional thrust model is established for the thrust estimation of the RBCC engine climbing process.The experimental results show the effectiveness of the model in the estimation.In addition,the method of mainstream and secondary flow action in pipeline rocket mode and ejector combustion mode is also carried out by this method.Based on the calculation method of the thrust,the trajectory planning of the climbing process of the RBCC dynamic aircraft with typical wave-body configuration is carried out.The plan is to optimize the minimum climb time,taking into account the dynamic pressure,air flow and other restrictions,and compared with the pure rocket power climb.The characteristics of the climbing trajectory of the RBCC powered aircraft,the thrust demand in the flight envelope,and the RBCC propulsion can save 5% fuel compare with pure rocket propulsion.Finally,the RBCC mainstream/secondary flow matching research is carried out by simulation method.The main purpose is to study the interaction between the mainstream and the secondary flow under the conditions of large rocket flow,low air flow and oxygen-rich/rich-rich secondary flow in the flight path.law.The study found some rules about the generation of thermal throats,and also proposed a method to increase the effect by secondary oxygen-rich/rich-burn control.