Flow structures downstream of the horizontal cylinder laid on a plane surface
Flow structures downstream of the horizontal cylinder laid on a plane surface
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放置在平面上的水平圆柱体下游的流动结构
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Aköz
中科院分区：
文献类型：
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作者：
M. Aköz
海底管道与水流相互作用产生复杂的旋涡流结构，引起管道周围的冲刷，对结构的稳定性构成威胁。本文利用粒子图像测速技术对水平床面上圆柱绕流的粘性流动进行了实验分析，以了解圆柱下游的旋涡流动特性。实验在雷诺数为1000 ≤ ReD ≤ 7000（基于圆柱直径）的闭环水槽中进行。为了详细评估圆柱体后面的流动结构的特性，给出了速度矢量场的瞬时和时间平均模式、相应的涡量等值线、流线拓扑和雷诺应力集中。确定了附面层从圆柱表面脱离的位置和下游一次分离区和二次分离区的长度。
AbstractThe complex vortical flow structure arises from the interaction between the flow and a pipeline on seabed, causing erosion scour around the pipeline, which is a threat to the stability of the structure. The viscous flow past a circular cylinder laid on a horizontal bed is analysed experimentally using the particle image velocimetry image technique to understand the vortical flow characteristics downstream of the cylinder. The experiments were conducted in a closed-loop water channel with Reynolds numbers, in the range of 1000 ≤ ReD ≤ 7000 based on the cylinder diameter. To provide a detailed evaluation of the properties of the flow structure behind the cylinder, instantaneous and time-averaged patterns of velocity vector field, corresponding vorticity contours, streamline topology, and Reynolds stress concentrations were presented. The point of the boundary layer detachment from the cylinder surface and the lengths of the primary and secondary downstream separation regions were determined as a fun...