A pair of Langmuir cells in two laboratory tanks (II) on generation mechanism
A pair of Langmuir cells in two laboratory tanks (II) on generation mechanism
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两个实验室水箱中的一对朗缪尔细胞（II）关于生成机制
DOI：
10.1007/bf02744383
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发表时间：
1998
影响因子：
2.3
通讯作者：
Yasutaka Kimura
中科院分区：
文献类型：
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作者：
S. Mizuno;H. Noguchi;Yasutaka Kimura
为了研究风浪池中的二次流，在两个展弦比为一阶的风浪池中系统地测量了垂直剖面上的平均流和横风向的平均流。一对朗缪尔池原来是由一个紧密结合的压力梯度沿着坦克和侧壁效应。也就是说，部分逆压梯度产生了抛物线横风剖面，中心线处的顺风气流最小，两侧壁沿着气流最大。结果表明，在回流最强的中心区域出现了上升流，这可能是由于风海流的卷吸作用。为了补偿这种上升流，从流动连续性开始沿两侧壁沿着出现下降流。由此产生的垂直环流形成了一对跨越跨度的朗缪尔环流，并用于维持由压力梯度形成的抛物线剖面。因此，在一次环流和二次环流之间通过回流在中心区的上涌存在正反馈机制。在两个水箱中测量的翼展平均顺风流的垂直剪切被发现是系统性的彼此不同。这种差异似乎取决于两个水箱中对流雷诺应力的大小。
Vertical and cross-wind profiles of mean currents were measured systematically in vertical cross-sections of two wind-wave tanks with aspect ratios of order one to study the secondary flow in the tanks. A pair of Langmuir cells turned out to be driven by a close combination of the pressure gradient along the tank and the side-wall effects. That is, part of the adverse pressure gradient produced a parabolic cross-wind profile with the smallest downwind current at the centerline and the largest current along the two sidewalls. As a result, upwelling occurred in the center zone where the return flow was strongest, probably because of the entrainment action of the wind-driven current. In order to compensate for this upwelling, downwelling occurred along the two side-walls from the flow continuity. The resulting vertical circulation formed a pair of Langmuir circulations across the span and served to maintain the parabolic profile formed by the pressure gradient. A positive feedback mechanism is thus found between the primary and secondary circulations through upwelling of the return flow in the center zone. Vertical shears of the span-averaged downwind current measured in two tanks were found to be systematically different from each other. This difference seems to depend on the magnitude of the advective Reynolds stresses in the two tanks.
影响因子：
--
作者：
E. Skyllingstad;D. Denbo
通讯作者：
E. Skyllingstad;D. Denbo