Rapid plunging of a body partly submerged in water

摘要

The water flow is studied when a thin body, part-submerged in originally still water, is plunged vertically downward. The rapid motion is at medium-to-large Reynolds number. The flow structure consists mainly of two viscous nonlinear layers, namely the unsteady boundary layer on the plunging body and unsteady wake along the trailing free surface, and one inviscid linear region in the bulk of the water. The former produce unsteady displacements which force the motion in the inviscid bulk, along with mixed boundary conditions, and control the evolutions of the wake-side and upper free surfaces.