Abstract: In order to understand the mechanism and rule of thermal throat in ramjet mode more clearly，three-dimensional numerical simulation has been carried out to study the influence factors on heat distribution in the flowpath of RBCC combustor，such as the position of fuel injection and cavity，the equivalence ratio of fuel，the flow rate of rocket，etc. The effects of different heat distribution on thermal throat were analyzed. The results show that heat distribution has a greater impact on the position of thermal throat compared with the amount of heat release under the premise of enough heat to form thermal throat. The methods like improving mixing and equivalence ratio of fuel to increase the amount of heat release will react with about 30% ~ 50% longer main exothermic region in which the thermal throat can not be generated. Therefore the application of these methods has limited influence on controlling the position of thermal throat. The location of thermal throat can be adjusted more effectively in a wide range by changing the flow rate of rocket which is easier to implement especially for the RBCC combustor. The adjusting range can reach 24% of the combustor length.

Key words: Rocket based combined cycle；Thermal throat；Main exothermic region；Numerical simulation

摘要： 为了更清楚地认识RBCC亚燃模态热力喉道生成机理与规律，通过三维数值模拟，研究了不同燃料喷注位置、凹腔位置、当量比以及火箭流量等影响RBCC燃烧室流道内放热分布的因素，分析了不同放热分布对于热力喉道生成的影响。研究结果表明在放热量足够形成热力喉道的前提下，放热分布相比放热量对热力喉道生成位置的影响更大，并且热力喉道不会形成于主放热区内，提高掺混、增加燃料当量比等使放热量增大的方法会伴随30% ~ 50%的主放热区间长度的增加，对于热力喉道生成位置的影响能力有限。对于RBCC燃烧室，调节火箭流量是一种更有效也更容易实现热力喉道位置宽范围调节的方法，调节范围可以达到燃烧室长度的24%。

关键词: 火箭基组合循环；热力喉道；主放热区；数值模拟