Abstract: An RBCC(Rocket-Based Combined Cycle)engine flowpath concept，which was used as the first stage propulsion system of a horizontal takeoff TSTO(Two Stage To Orbit)aircraft，was proposed. An integrated inner flowpath(inlet，combustor and nozzle)rapid performance analysis model was established and the flowpath was designed. A variable geometry intake，a combustor which incorporated pylon and cavity for flame holding anda single-expansion-ramp-nozzle were selected to form the flowpath. A validated rapid analysis model was em.ployed to compute the performance of RBCC combustor and comparisons between the 3-D simulations and the en.gine performance analysis model results on the afterbody flowfield had been performed. An RBCC engine applica.tion to a two-stage-to-orbit mission propulsion system was discussed and the propulsion system was analyzed.The performance of the RBCC propulsion system on the flight envelope was evaluated. The results demonstratethat the vehicle with a 280 tonnes launch weight could place a 4 tonnes payload in low earth orbit.

Key words: Rocket-based combined cycle；Two stage to orbit；Integrated flowpath；Performance analysis RBCC

摘要： 针对以火箭基组合循环( RBCC)发动机作为水平起飞两级入轨( TSTO)运载器第一级动力系统的方案，建立了进气道 -燃烧室 -尾喷管一体化流道耦合性能快速计算模型，初步设计了 RBCC发动机一体化内流道。 RBCC发动机使用变结构进气道，采用支板 /凹腔相结合实现火焰稳定的燃烧室以及单侧膨胀尾喷管；应用经过校验的性能分析模型进行 RBCC燃烧室性能快速计算；对比分析了性能分析模型与三维数值计算获得的发动机出口状态参数对于飞行器后体流场的影响性；完成了 RBCC为动力的两级入轨方案飞行器动力系统的性能分析与计算；分析评估了飞行弹道条件下 RBCC推进系统的性能。计算结果表明 :飞行器起飞质量 280t时，可以完成运送4t载荷进入近地轨道的任务。

关键词: 火箭基组合动力循环；两级入轨；一体化流道；性能分析模型