一次火箭参数对RBCC引射模态性能的影响

Effect of primary rocket parameters on the performance of RBCC (rocket based combined cycle) in ejector mode

关键词:  复合式发动机  引射模态  性能分析

Key words:  Compound engine  Ejector mode  Performance analysis

摘要:

应用经过校验的三维湍流有限体积数值算法,对引射模态下RBCC模型不同一次引射火箭结构和工作参数条件下的多种工作状态进行了模拟。结果发现:提高一次火箭燃烧室工作压强,二次流量增加,系统推力增加,混合效果增强;一次火箭喷管形状直接影响引射掺混效果,但在保证足够一次流量的前提下,方形管道中可以使用锥形一次喷管,不会带来性能上的较大差异;一次火箭喷管数目增加,掺混质量提高;一次喷管扩张半角的改变不会影响二次引入流量,但会影响掺混效果和一次火箭自身推力;一次喷管面积膨胀比的变化,不会影响二次引入流量,但会改变混合效果。

Abstract:

Applying 3-D turbulent finite volume numerical algorithm validated, different operation status of Rocket Based Combined Cycle (RBCC) model with different structures and working conditions of primary rocket were simulated in ejector mode. It was found that: 1, by increasing the chamber pressure of the primary rocket, the second air mass flow rate, the total thrust of the model and the mixing efficiency will increase. 2, the shape of primary rocket nozzle can affect the ejector-mixing efficiency dramatically. However, with the promise of providing enough primary mass flow, cone-shaped primary nozzle can be utilized in the rectangular main duct of RBCC model, which will not bring obvious reduction to the system performance. 3, by increasing primary nozzle number, the mixing quality will improve. 4, the expansion half-angle of primary nozzle can not change the second mass flow rate. But can affect the mixing efficiency and thrust of primary rocket. 5, the change of area expansion ratio of the primary nozzle will not effect second mass flow rate. But it will change the mixing efficiency.