Flow visualisation of a pitching and heaving hydrofoil
Flow visualisation of a pitching and heaving hydrofoil
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俯仰和垂荡水翼的流动可视化
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
E. Hassan
中科院分区：
文献类型：
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作者：
T. Lau;R. Kelso;E. Hassan
鱼启发的起伏和俯仰箔进行了研究，在水洞中使用染料可视化，在雷诺数870和3480（基于弦长）和斯特劳哈尔数0.06和1.37之间。研究了尾流流型随Strouhal数的变化规律。观察到三种不同的尾流状态：拖曳尾流、过渡尾流和推力尾流。拖曳尾流由一个常规的卡门涡街和一系列“初级”停止-启动涡组成，而推力尾流由一个反向卡门涡街组成，通常在游动的鱼中观察到。过渡尾流制度，这发生在约0 2 St 0 3，被解释为动量平衡的尾流，其中由翼型开发的推力约平衡其产生的阻力。观察到该尾流由一个直列式涡街或成对涡型组成。
A fish-inspired heaving and pitching foil was investigated in a water tunnel using dye visualisation, at Reynolds numbers between 870 and 3480 (based on the chord length) and Strouhal numbers between 0.06 and 1.37. The variation of the wake pattern with respect to the Strouhal number was investigated. Three different wake regimes were observed a drag wake, a transition wake and a thrust wake. The drag wake consisted of a combination of a regular Karman street and an array of ’primary’ stop-start vortices, whereas the thrust wake consisted of a reverse Karman vortex street, commonly observed in swimming fish. The transition wake regime, which occurs at approximately 0 2 St 0 3, is interpreted as a momentum balanced wake, where the thrust developed by the foil approximately balances its produced drag. This wake was observed to either consist of an in-line vortex street, or a paired vortex pattern.