On the collision of a rigid pendulum with a deformable mambrane in a viscous fluid

In Nature and technology, the interaction between two bodies is always mediated by a fluid that, depending on its properties, can heavily influence the dynamics of the whole system. While for gasses,  the fluid density is much smaller than those of the bodies and the presence of the former can be neglected, if the fluid is a liquid, its inertia and viscous stresses produce significant loads and its effect has to be accounted for.

In this study we have considered a rigid spherical pendulum impacting on thin rubber membrane in water either experimentally (by high-speed contour tracking and particle image velocimetry) and by numerical simulations of the Navier–Stokes equations coupled with a fluid/structure interaction algorithm. We have found that general model that is flexible enough to cope with arbitrary deformable objects is missing from the literature and in this study we aim at progressing in that direction. The properties of both, pendulum and membrane have been changed independently and different impact regimes have been reproduced.

The most common impact models are tested and benchmarked against the experimental results and a physics based general collison model is presented and validated.