On some properties of the pressure in nonlinear two-dimensional potential flow with a free surface

Abstract

Two-dimensional nonlinear free surface flows are nowadays routinely simulated on computers. In the context of the potential flow theory, fine details of the free surface motion can be captured. However, few studies focus on the flow beneath the free surface. The novelty of the present work lies in identifying lines where the pressure gradient is colinear with one eigenvector of the pressure Hessian matrix. The spatial and temporal evolution of these lines offers new insights into the complexity of highly nonlinear flows. This pressure characteristic is used to revisit four more or less recent research studies on breaking waves.