The Hydrodynamics of Hard-Chine Sections Entering Water

Abstract

While landing Wing-in Ground Effect (WIG) craft are exposed to large hydrodynamic forces which can lead to structural damages. Sea loads can be predicted by solving the free surface problem, known as water entry. The problem has been studied for rigid bodies until most recently, when researchers hypothesized that the structural response of the body can also influence the hydrodynamic pressures. This paper aims to provide deeper understanding of the impact loads during the water entry process of a hard chine section for the case of a common WIG Craft section. A Finite Volume Method (FVM) based computational fluid-structure interaction model is used to solve multi-physics and quantitative comparisons are made between experimental and computational data. Simulations demonstrate that structural dynamics can attenuate the pressure acting on body walls. The deadrise angle, speed in way of water entry and rigidity of the solid body are shown to affect the dynamic response with equivalent stresses maximized and then decaying over time near the chine.