Jet formation at interaction of a vibrating plate with liquid

摘要

In this work, we experimentally investigate the mechanism of jet formation on liquid surface near the edge of a vibrating plate that is partially immersed in the liquid. Under the conditions of resonant bending vibrations, the vibrating plate excites capillary waves in the form of Faraday ripples on the surface of the liquid layer wetting the plate surface. Two-dimensional capillary waves also appear on the curved surface of the liquid near the edges of the vibrating plate. The vibrations of the plate area generate hydrodynamic pressure on the liquid surface, which initiates surface eddy flows. At a certain position of the vibrating plate in the liquid, capillary oscillations in the form of standing waves appear along the boundary of the wetting layer of the liquid, directly under the free edge of the plate. The vibrations of the plate edge modulate the standing waves in the transverse direction, which results in the periodic variation of the surface curvature of the wetting liquid layer, from negative to positive values. The inertia forces, periodically varying with the frequency of the plate vibrations, combined with the Laplace pressure, in the excited standing capillary waves on the surface flow under the plate edge, initiates the periodic ejection of particles of the liquid forming a jet.