Air-cushioning below an impacting wave-structured disk: Free-surface deformation and slamming load
Yee Li Fan, Utkarsh Jain, Devaraj van der Meer
Abstract
A radially symmetric sinusoidal wave structure is imprinted on an impacting circular disk to modulate the way the disk forces the free water surface. The experiments support the argument that the surface elevation around the disk edge prior to impact is an instability of the Kelvin-Helmholtz type, as the free surface resonates when the forcing wavelength on the disk is close to the most unstable wavelength predicted by theory. Besides, our wave-structured disk is also found to promote gradual inertial wetting of the impacting surface to effectively retain the entrapped air pocket (as shown in the figure), which, in turn, mitigates the peak impact force.
Topics & Concepts
SlammingFree surfaceCushioningMechanicsWavelengthForcing (mathematics)PhysicsOpticsMaterials scienceComposite materialAtmospheric sciencesHullFluid Dynamics Simulations and InteractionsFluid Dynamics and Heat TransferCoastal and Marine Dynamics