Numerical investigation on entry of an inclined cylinder into water under uniform current and wind

Abstract

The entry of a circular cylinder into water represents the problem of the coupling of multiphase flow with highly unsteady and nonlinear dynamics. Few studies have examined the influence of the initial angles of inclination of the object on the evolution of the cavity and the multiphase flow field under impact-induced loads in the presence of currents and wind. In this study, we develop a three-dimensional numerical model in OpenFOAM® to simulate and analyze this entire process. An overset mesh technique was used to reproduce the entire process of the entry of a circular cylinder into water as well as the formation, pinch-off, and collapse of the cavity. A comparison between our numerical results and previously published test data from the laboratory confirmed that the proposed numerical model can accurately simulate the dynamic characteristics of the multiphase flow field. The mode and time series of the closure of the cavity varied with the initial angles of inclination of the cylinder, and in turn influenced its translational and rotational characteristics of motion. The pressure, velocity and vortex structures suggest that the evolution and distribution of multiphase flow field for upstream and downstream water entry cases have varied characteristics.