fluid structure interaction sub-field discipline fluid mechanics

This article addresses the interaction of two coaxial cylinders separated by a thin fluid layer. The cylinders are flexible, have a finite length, and are subject to a vibration mode of an Euler–Bernoulli beam. Assuming a narrow channel, an inviscid and linear theoretical approach is carried out, leading to a new simple and tractable analytical expression of the fluid forces.

This work deals with the small oscillations of two circular cylinders immersed in a viscous stagnant fluid. A new theoretical approach based on an Helmholtz expansion and a bipolar coordinate system is presented to estimate the fluid forces acting on the two bodies. We show that these forces are linear combinations of the cylinder accelerations and velocities, through viscous fluid added coefficients. To assess the validity of this theory, we consider the case of two equal size cylinders, one of them being stationary while the other one is forced sinusoidally.