Experiments on the water entry of asymmetric wedges using particle image velocimetry

Abstract

In this work, we experimentally characterize the water entry of an asymmetric wedge into a quiescent fluid through particle image velocimetry (PIV). The wedge enters the water surface with an orthogonal velocity falling from a fixed height. We systematically vary the heel angle to elucidate the effect of asymmetric impact on the flow physics and on the fluid-structure interaction. The pressure field in the fluid is reconstructed from PIV data by integrating the Poisson equation. We find that the impact configuration significantly influences both the velocity and the pressure field, ultimately, regulating the hydrodynamic loading on the wedge. Specifically, as the heel angle increases, the location of maximum velocity of the flow moves from the pile-up region to the keel. At the same time, the pressure field significantly decreases in the vicinity of the keel, reaching values smaller than the atmospheric pressure. The spatiotemporal evolution of the hydrodynamic loading is thus controlled by the heel angle, with larger heel angles resulting into more rapid and sustained impacts.