On the structure of jets in a crossflow
On the structure of jets in a crossflow
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横流射流结构研究
DOI：
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发表时间：
1985
影响因子：
3.7
通讯作者：
J. Andreopoulos
中科院分区：
文献类型：
--
作者：
J. Andreopoulos
针对从发展中的管流垂直射入横流的射流的各种速度比和雷诺数，进行了光谱分析和流动可视化。结果是完整的，其中射流与横流的速度比 R 为 0.5，并对各种湍流量进行了条件平均值。独特的条件采样技术通过同时使用两个条件函数将湍流射流、无旋射流、湍流横流和无旋横流的贡献分开。间歇因子分布表明，无旋横流侵入管道，但对平均湍流量没有贡献，而射流管无旋流在出口上方区域中对平均湍流量有显着贡献，在该区域边界层涡流与管道涡流之间开始发生相互作用。再往下游，迎面而来的边界层涡流对统计平均值的贡献显着减少。下游的发展主要取决于相互作用的湍流场的平均相对涡流大小。
Spectral analysis and flow visualization are presented for various velocity ratios and Reynolds numbers of a jet issuing perpendicularly from a developing pipe flow into a crossflow. The results are complete with conditional averages of various turbulent quantities for one jet-to-cross-flow velocity ratio R of 0.5. A unique conditional-sampling technique separated the contributions from the turbulent jet flow, the irrotational jet flow, the turbulent crossflow and the irrotational crossflow by using two conditioning functions simultaneously. The intermittency factor profiles indicate that irrotational cross-flow intrudes into the pipe but does not contribute to the average turbulent quantities, while the jet-pipe irrotational flow contributes significantly to them in the region above the exit where the interaction between the boundary-layer eddies and those of the pipe starts to take place. Further downstream, the contributions of the oncoming boundary-layer eddies to the statistical averages reduce significantly. The downstream development depends mainly on the average relative eddy sizes of the interacting turbulent fields.