Mechanics of flow over ripples and dunes
Mechanics of flow over ripples and dunes
复制标题
涟漪和沙丘上的流动力学
DOI：
10.1029/jc094ic06p08146
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发表时间：
1989
影响因子：
--
通讯作者：
J. Smith
中科院分区：
文献类型：
--
作者：
J. Nelson;J. Smith
本文提出了二维有限振幅底形上流速场和边界剪应力场的一个简单预测模型，并将该模型的结果与水槽资料进行了比较。用姆克林和Smith（1986）的方法处理了由于底形顶部附近的流动分离而产生的尾流，以及随后该尾流区与流动再附着点下游发展的不均匀附面层的相互作用。他们的模型进行了修改，以考虑到更准确的短波长障碍物的流量响应，并包括从上游底形的影响，因为这些唤醒合并在内部。该理论还扩展到包括区域之间的底形波峰和再附着点，从而提供了一个空间上完整的速度和剪切应力场。计算结果被认为是在良好的协议与实验室测量采取了固定的床型使用激光多普勒测速仪。我们的有限振幅流动模型，以产生准确的预测的流体动力学效应，最终负责的形态发育良好的自然底形。
A simple predictive model for velocity and boundary shear stress fields over two-dimensional bedforms of finite amplitude is presented herein, and the results of that model are compared with flume data. The production of a wake due to separation of the flow near the bedform crest and the subsequent interaction of this wake region with a developing nonuniform boundary layer downstream of the flow reattachment point are treated using the method of McLean and Smith (1986). Their model is modified in order to take account of the flow response to short-wavelength obstructions more accurately and to include the effects of wakes from upstream bedforms as these wakes coalesce in the interior. The theory is also extended to include the region between the bedform crest and the reattachment point, thereby providing a spatially complete field of velocity and shear stress. Results of the calculations are found to be in good agreement with laboratory measurements taken over immobile bedforms using a laser-Doppler velocimeter. Our finite amplitude flow model is shown to yield accurate predictions of the fluid dynamical effects ultimately responsible for the morphology of well-developed natural bedforms.