Fluid-structure interaction of two bodies in an inviscid fluid
Fluid-structure interaction of two bodies in an inviscid fluid
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DOI：
10.1063/1.3485063
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发表时间：
2010-10
影响因子：
4.6
通讯作者：
Andrew A. Tchieu;D. Crowdy;A. Leonard
中科院分区：
文献类型：
--
作者：
Andrew A. Tchieu;D. Crowdy;A. Leonard
研究了浸没在二维无粘流体中的任意两个物体的相互作用。在给定物体的线速度和角速度的情况下，两个物体周围零循环的势流问题的解归结为在满足边界条件的共形映射域中确定合适的洛朗级数。然后利用势流解通过推广的Blasius公式确定作用在每个物体上的力和力矩。目前的公式被应用于两个例子。首先，研究了无界域中两个刚性圆柱体相互作用的情况。为验证目的，确定了具有规定运动强迫运动的两个圆柱体上的力，并与以前的结果进行了比较。然后，我们研究了一个“自由”圆柱体在另一个“自由”圆柱体强制自由运动时的响应。这种强制自由的情况被用来证明在水上运动中吃水的水动力效益。在两个中性浮力的圆柱体的情况下，尾部的圆柱体能够获得与其惯性力的数量级相同的大推力。此外，还研究了任意初始条件自由-自由条件下两个圆柱体的耦合相互作用，以显示在无粘流体存在和存在的情况下完全碰撞的差异。对于特定范围的碰撞参数，在碰撞之前，流体会使圆柱体路径发生足够的偏转，从而严重影响物体的长时间轨迹。在第二个例子中，研究了两个平板的拍打。结果表明，各板之间的相互作用可以在某一时刻产生净力和力矩，但对于无旋势流中的理想正弦运动，系统中心不存在净力和力矩。
The interaction of two arbitrary bodies immersed in a two-dimensional inviscid fluid is investigated. Given the linear and angular velocities of the bodies, the solution of the potential flow problem with zero circulation around both bodies is reduced to the determination of a suitable Laurent series in a conformally mapped domain that satisfies the boundary conditions. The potential flow solution is then used to determine the force and moment acting on each body by using generalized Blasius formulas. The current formulation is applied to two examples. First, the case of two rigid circular cylinders interacting in an unbounded domain is investigated. The forces on two cylinders with prescribed motion forced-forced is determined and compared to previous results for validation purposes. We then study the response of a single “free” cylinder due to the prescribed motion of the other cylinder forced-free. This forced-free situation is used to justify the hydrodynamic benefits of drafting in aquatic locomotion. In the case of two neutrally buoyant circular cylinders, the aft cylinder is capable of attaining a substantial propulsive force that is the same order of magnitude of its inertial forces. Additionally, the coupled interaction of two cylinders given an arbitrary initial condition free-free is studied to show the differences of perfect collisions with and without the presence of an inviscid fluid. For a certain range of collision parameters, the fluid acts to deflect the cylinder paths just enough before the collision to drastically affect the long time trajectories of the bodies. In the second example, the flapping of two plates is explored. It is seen that the interactions between each plate can cause a net force and torque at certain instants in time, but for idealized sinusoidal motions in irrotational potential flow, there is no net force and torque acting at the system center.