Numerical investigation on thermal behaviors of active-cooled strut in RBCC engine
Numerical investigation on thermal behaviors of active-cooled strut in RBCC engine
复制标题
RBCC发动机主动冷却支柱热行为数值研究
DOI：
10.1016/j.applthermaleng.2016.11.100
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发表时间：
2017
影响因子：
6.4
通讯作者：
Li WQ
中科院分区：
文献类型：
--
作者：
Hou Z. Y.;He G. Q.;Li W. Q.;Qin F.;Wei X. G.;Jing T. T.;Li WQ
将支柱喷射器与吸气式发动机集成是提高燃油/空气混合和燃烧效率的有效方法。在本研究中，设计了一种具有主动冷却结构的不锈钢支柱，用于火箭联合循环（RBCC）发动机恶劣燃烧室环境下的热保护。提出了将推力室中的湍流燃烧与支柱中的对流换热相结合的数值模型。在6马赫飞行条件下，评估了四种煤油冷却剂质量流量下支柱内的流动和热行为。数值压力与实验数据吻合良好。结果表明，采用设计的冷却结构，支柱温度保持在允许的范围内。由于支柱角部的热阻较高，在支柱后部发现了最高温度 (1100 K)。前缘的扰动和支柱后部的流动分离导致支柱边界附近的涡度增大和速度减小。由于歧管入口处的突然压降，歧管中的冷却剂速度和热效率均增加。
Integrating strut ejector with air-breath engine is an effective method of enhancing fuel/air blend and combustion efficiency. In the present study, a stainless steel strut with active cooling structure is designed for thermal protection in severe combustor environment in Rocket Based Combined Cycle (RBCC) engine. The numerical model is proposed that conjugates turbulent combustion in thrust chamber and convective heat transfer in strut. The flow and thermal behaviors in the strut are evaluated under four mass flow rates of kerosene coolant at the flight condition of Mach 6. The numerical pressures are in good agreement with the experimental data. Results indicate that the strut temperature is maintained within the allowable limit with the designed cooling structure. The highest temperature (1100 K) is discovered at the rear of the strut due to the high thermal resistance at the strut corner. The perturbation at leading edge and the flow separation at strut back lead to vorticity augmentation and velocity decrease at the vicinity of strut bound. Both coolant velocity and thermal efficiency increase in the manifold due to the sudden pressure drop at the manifold entrances.