Turbulence structure of a reattaching mixing layer
Turbulence structure of a reattaching mixing layer
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再附着混合层的湍流结构
DOI：
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发表时间：
1981
影响因子：
3.7
通讯作者：
P. Bradshaw
中科院分区：
文献类型：
--
作者：
C. Chandrsuda;P. Bradshaw
热线测量的二阶和三阶平均产品的速度波动已经在后面的流动步骤与薄，层流边界层的顶部的步骤。测量延伸到一个距离约12步的高度下游的步骤，并包括部分的再循环流动区域：近似的热线结果的有效性限制。基于台阶高度的雷诺数约为105，混合层在再附着前充分湍流（完全三维涡流），与以前一些工作者的结果相比，相当接近于自我保护。湍流量的快速变化发生在再附着区：雷诺切应力和三重积急剧下降，主要是因为固体表面对大涡的限制。在湍流能量和剪切应力平衡的条款也迅速变化，但仍然远离自我保存的边界层状态，即使在测量区域的结束。
Hot-wire measurements of second- and third-order mean products of velocity fluctuations have been made in the flow behind a backward-facing step with a thin, laminar boundary layer at the top of the step. Measurements extend to a distance of about 12 step heights downstream of the step, and include parts of the recirculating-flow region: approximate limits of validity of hot-wire results are given. The Reynolds number based on step height is about 105, the mixing layer being fully turbulent (fully three-dimensional eddies) well before reattachment, and fairly close to self-preservation in contrast to the results of some previous workers. Rapid changes in turbulence quantities occur in the reattachment region: Reynolds shear stress and triple products decrease spectacularly, mainly because of the confinement of the large eddies by the solid surface. The terms in the turbulent energy and shear stress balances also change rapidly but are still far from the self-preserving boundary-layer state even at the end of the measurement region.