Fluid-structure interaction of two bodies in an inviscid fluid
A. A. Tchieu, D. Crowdy, A. Leonard
2010
Physics of Fluids
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
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... mulas. 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-forced͒ 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-free͒. 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-free͒ 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. Downloaded 29 Nov 2010 to 131.215.220.185. Redistribution subject to AIP license or copyright; see http://pof.aip.org/about/rights_and_permissions 107101-4 Tchieu, Crowdy, and Leonard Phys. Fluids 22, 107101 ͑2010͒ Downloaded 29 Nov 2010 to 131.215.220.185. Redistribution subject to AIP license or copyright; see http://pof.aip.org/about/rights_and_permissions 107101-12 Tchieu, Crowdy, and Leonard Phys. Fluids 22, 107101 ͑2010͒ Downloaded 29 Nov 2010 to 131.215.220.185. Redistribution subject to AIP license or copyright; see http://pof.aip.org/about/rights_and_permissions
doi:10.1063/1.3485063
fatcat:pb5bchhys5ev5pmzwq4bn34reu