Self-propelled plate in wakes behind tandem cylinders
Self-propelled plate in wakes behind tandem cylinders
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串联气缸后面尾流中的自推进板
DOI：
10.1103/physreve.100.033114
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发表时间：
2019
影响因子：
2.4
通讯作者：
Lu Xi-Yun
中科院分区：
文献类型：
--
作者：
Wang Wenjiang;Huang Haibo;Lu Xi-Yun
鱼类可以利用环境漩涡来节省移动的成本。从多个物理对象脱落的复杂流体动力学可能会显着影响鱼类避难（保持静止）。以自推进拍动平板为模型，数值研究了拍动平板在串列双圆柱尾迹中的运动。在大多数模拟中，板块在流动到来之前在其初始位置隆起（释放I型）。在典型的尾流模式中，板可以保持静止、向上游漂移或向下游漂移。得到了这些模态在涡脱落模式下的平面相图，即扑动振幅。据观察，该板是能够保持静止在多个平衡位置后，它被释放。同时，板所需的最小振幅和输入功率似乎与脱落涡强度成反比。同时研究了释放方式对释放效果的影响。如果板保持静止不动，直到涡脱落完全发展（释放类型II），那么板能够在某些平衡位置保持静止，但拍动板对脱落涡的影响非常小。而在I型中，通过调节旋涡脱落的相位，释放板能够达到更多的平衡位置。在第一式中，前扑翼的努力并不是徒劳的，因为尽管它消耗更多的能量，但之后保持静止变得更容易。探讨了相关机制。
Fish may take advantage of environmental vortices to save the cost of locomotion. The complex hydrodynamics shed from multiple physical objects may significantly affect fish refuging (holding stationary). Taking a model of a self-propelled flapping plate, we numerically studied the locomotion of the plate in wakes of two tandem cylinders. In most simulations, the plate heaves at its initial positionbefore the flow comes (releasing Style I). In the typical wake patterns, the plate may hold stationary, drift upstream, or drift downstream. The phase diagrams of these modes in theplane for the vortex shedding patterns were obtained, whereis the flapping amplitude. It is observed that the plate is able to hold stationary at multiple equilibrium locations after it is released. Meanwhile, the minimum amplitude and the input power required for the plate seem inversely proportional to the shedding vortex strength. The effect of releasing style was also investigated. If the plate keeps stationary and does not flap until the vortex shedding is fully developed (releasing Style II), then the plate is able to hold stationary at some equilibrium locations but the flapping plate has a very minor effect on the shedding vortices. However, in Style I, the released plate is able to achieve more equilibrium locations through adjusting the phase of vortex shedding. The effort of the preflapping in Style I is not in vain, because although it consumes more energy, it becomes easier to hold stationary later. The relevant mechanism is explored.