Detailed parametric investigations on drag and heat flux reduction induced by a combinational spike and opposing jet concept in hypersonic flows
Detailed parametric investigations on drag and heat flux reduction induced by a combinational spike and opposing jet concept in hypersonic flows
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DOI：
10.1016/j.ijheatmasstransfer.2018.05.013
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发表时间：
2018-11
影响因子：
5.2
通讯作者：
Min Ou;Li Yan;Wei Huang;Shibin Li;Lang-quan Li
中科院分区：
文献类型：
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作者：
Min Ou;Li Yan;Wei Huang;Shibin Li;Lang-quan Li
在目前的研究中，一种新的组合反向射流和穗概念引起的流场行为进行了数值研究。首先对湍流模型的选取和第一网格点离壁高度Δx的选取进行了综合分析。重点研究了喷管直径（d 0）、塞体长径比（L/D）和射流压力比（PR）对流场结构、气动阻力和热性能的影响。结果表明，当0为2 mm时，在单尖头钝体上加入反向喷流对改善高阻高热环境没有帮助。而组合热防护系统在0为4 mm时对减阻减热有较大贡献，壁面Stanton数St和阻力系数Cd分别下降45%和38%。当L/D从1.0增加到1.5时，壁面热流密度、静压和阻力系数都有明显的下降，而当L/D从1.5增加到2.0时，这些指标的下降幅度并不明显。同时，反向射流的引入在钉头上游形成回流区，当L/D增大到2.0时，在气动盘下游也形成回流区。这两个回流区都显著地缓解了气盘所承受的高温。
In the current study, the flow field behavior induced by a novel combinational opposing jet and spike concept has been investigated numerically. A comprehensive analysis on the selections of the turbulence model and the height of the first grid point off the wall (Δx) has been conducted firstly. Then, this paper mainly focuses on the influences of the nozzle diameter (d0), the length-to-diameter ratio of the aerospike (L/D) and the jet pressure ratio (PR) on the flow field structures, the aerodynamic drag and heat properties. The results show that whend0is 2 mm, adding the opposing jet to the single spiked blunt body has no help in modifying the high drag and heat environment. However, the combinatorial thermal protection system has a great contribution to reduce the drag and heat whend0is 4 mm, with 45% and 38% drop on the wall Stanton number (St) and drag coefficient (Cd) respectively. The values of the wall heat flux, the static pressure and the drag coefficient decrease apparently whenL/Dincreases from 1.0 to 1.5, while the drop rates of these indexes seem not so obvious whenL/Drises from 1.5 to 2.0. Meanwhile, the introduction of the opposing jet creates a recirculation zone upstream the spike head, and there is a recirculation zone emerges downstream the aerodisk as well whenL/Dincreases to 2.0. Both of the recirculation zones have alleviated the high temperature the aerodisk sustained significantly.