摘要
为了检查氧化射流对推力矢量角、二次燃烧效率和燃烧室压力的影响，使用不同的喷射技术将惰性气体(氮气)和纯氧喷射到包括可燃组分的主流中，在分流段和喉部的不同位置。二维数值模拟采用雷诺平均navier-stokes方程，三维数值模拟采用大涡模拟。通过纹影实验验证了数值方法的有效性，并用liutex-omega方法识别了涡。分析了涡结构和流动特性。结果表明，在相同流量下，纯氧的矢量控制效果仅在发散段优于氮气，而在发散段和喉部均低于氮气。然而，通过改进的矢量控制，在纯氧的情况下，在较低的流速下实现矢量角的峰值。当仅在分流段引入二次流时，纯氧情况下对应峰值的流量比氮气情况下约早14.3%。纯氧射流的引入提高了一次流的二次燃烧效率，但程度有限。另外，当喷嘴在喉部引入时，纯氧箱在调节燃烧室压力方面的作用低于氮箱。在流动细节方面，当动量通量比较小时，尾下涡取代尾主涡成为最大涡量级涡。
Abstract
To examine the impact of oxidative jets on the thrust vector angle, secondary combustion efficiency, and combustion chamber pressure, inert gas (nitrogen) and pure oxygen are injected into the primary flow, which includes combustible components, at various locations in the divergence section and throat using different injection techniques. The simulations utilize Reynolds-averaged Navier-Stokes equations coupled with the SST k-ω turbulence model in two-dimensional numerical simulations and large-eddy simulation in three-dimensional studies. The numerical method is validated through schlieren experiments, and the vortex is identified using the Liutex-Omega method. The vortex structures and flow characteristics are analyzed. The results indicate that, at the same flow rate, the vector control effect of pure oxygen is superior to nitrogen only in the divergence section, but inferior to nitrogen in both the divergence section and throat. However, with improved vector control, the peak of the vector angle is achieved at a lower flow rate in the case of pure oxygen. When the secondary flow is introduced only in the divergence section, the flow ratio corresponding to the peak point in the pure oxygen case is approximately 14.3% earlier than that in the nitrogen case. The introduction of the pure oxygen jet enhances the secondary combustion efficiency of the primary flow, but to a limited extent. Additionally, when the jet is introduced at the throat, the effect of the pure oxygen case on adjusting the combustion chamber pressure is inferior to that of the nitrogen case. Concerning flow details, the trailing lower vortex replaces the trailing major vortex to become the highest magnitude vortex when the momentum flux ratio is small.
NETL
NSTL
Hindawi Publishing Group