REVIEW - REVIEW OF FLOW INTERFERENCE BETWEEN 2 CIRCULAR-CYLINDERS IN VARIOUS ARRANGEMENTS
REVIEW - REVIEW OF FLOW INTERFERENCE BETWEEN 2 CIRCULAR-CYLINDERS IN VARIOUS ARRANGEMENTS
复制标题
DOI：
10.1115/1.3448871
复制
发表时间：
1977-01-01
影响因子：
2
通讯作者：
ZDRAVKOICH, MM
中科院分区：
文献类型：
--
作者：
ZDRAVKOICH, MM
有无数种可能的两人组合 平行的圆柱体与接近的流动方向成直角。 在无限排列中，可以确定两个不同的组： 组中，气缸串联布置，一个在另一个后面， 在第二组中，圆柱体面向流动侧， 以任何横向间距并排放置。所有其他纵向和 横向间隔表示交错布置。串联布置 将首先得到治疗。对先前研究的一项重要调查显示， “奇怪”的特征，被许多作者观察到和忽视了。的 涡脱落的不连续性意味着， 两个圆柱体上的阻力是预期的。前面的尺寸 (gap)下游气缸的压力和两者的基础压力 不同间距的圆柱体在某些临界点处显示出不连续的“跳跃”， 间距。不连续性是由一个稳定流的突然变化引起的 以临界间距将图案转换为另一个图案。本文给出了新的解释， 两个圆柱体阻力的现有数据。Reynolds的影响 数字和表面粗糙度进行了详细的处理。随后，两名 考虑与接近流并排布置的圆柱体。所有的 关于测量力的可用数据与附加的 在阻力和升力的间歇变化范围内进行测量。的 每个气缸周围的非对称流型的非对称性产生两个 阻力的两个备选值与 升力干涉力系数的引入揭示了 圆柱体所经受的两种不同力的物理起源， 并排排列。最后，报道最少的两个交错排列的 汽缸被检查。各种安排被分为几类 根据升力的符号，或者阻力是否更大， 小于单个气缸的压力。阻力和升力的测量 对于各种布置，揭示了升力的两种不同状态。在一个 在这种状态下，指向上游圆柱体尾流的升力是由于 将气流夹带到上游充分发展的尾流中 缸在该状态下，当 下游圆柱靠近上游尾迹边界。在第二种制度中， 在非常小的间距处，由于强烈的间隙，升力变得非常大 流，它取代了上游气缸的尾流。最大升力 下游圆柱体靠近上游圆柱体的水平轴线时， 缸对于某些交错布置，升力不连续， 发现并归因于差距流的非线性。
There are infinite numbers of possible arrangements of two parallel cylinders positioned at right angles to the approaching flow direction. Of the infinite arrangements, two distinct groups may be identified: in one group, the cylinders are in a tandem arrangement, one behind the other at any longitudinal spacing; and in the second group, the cylinders face the flow side by side at any transverse spacing. All other combinations of longitudinal and transverse spacings represent staggered arrangements. The tandem arrangement will be treated first. A critical survey of previous research revealed some “odd” features which had been observed and overlooked by various authors. The discontinuity of vortex shedding implies that a similar discontinuity should be expected for the drag force on both cylinders. The measurements of the front (gap) pressures of the downstream cylinder and the base pressures of both cylinders at various spacings reveal a discontinuous “jump” at some critical spacing. The discontinuity is caused by the abrupt change from one stable flow pattern to another at the critical spacing. A new interpretation is given for the existing data on the drag force for both cylinders. The effects of Reynolds number and surface roughness are treated in some detail. Following this, two cylinders arranged side by side to the approaching flow are considered. All the available data on measured forces are compiled together with additional measurements in the range of intermittent changes of drag and lift forces. The bistable nature of the asymmetric flow pattern around each cylinder produces two alternative values of the drag force coupled with two alternative values of the lift force. The introduction of the interference force coefficient exposes the physical origin of two different forces experienced by the cylinders when arranged side by side. Finally, the least reported arrangement of two staggered cylinders is reviewed. The various arrangements are grouped into classes according to the sign of the lift force, or whether the drag force is greater or less than that for a single cylinder. The measurements of drag and lift forces for various arrangements reveal two different regimes for the lift force. In one regime, the lift force directed toward the wake of the upstream cylinder is due to the entrainment of the flow into the fully developed wake of the upstream cylinder. The lift force in this regime reaches a maximum value when the downstream cylinder is near to the upstream wake boundary. In the second regime, at very small spacings, the lift force becomes very large due to an intense gap flow which displaces the wake of the upstream cylinder. The maximum lift force occurs with the downstream cylinder near to the horizontal axis of the upstream cylinder. A discontinuity in the lift force for some staggered arrangements is found and attributed to the bistable nature of the gap flow.