Numerical investigations of hydrodynamic performance of dynamically installed anchors subjected to current considering anchor geometric effects

Abstract

Dynamically installed anchor is an innovative and cost-effective technology in marine foundation engineering. However, most of the existing researches on the hydrodynamic characteristics of dynamically installed anchors are limited to their free-fall installation performance in water without considering the action of marine environmental loads such as current. Therefore, this study aims to investigate the hydrodynamic performance of dynamically installed anchors subjected to current in a systematical manner. A complete three-dimensional CFD model is firstly established using “dynamic model analysis” method. Then, the effects of anchor geometric characteristics on the installation efficiency (i.e., penetration velocity and drag coefficient) and installation positioning accuracy (i.e., lateral velocity and displacement, and inclination angle) of the anchors subjected to current are systematically studied using the established CFD model. The influences of current velocity, current direction and geometric characteristics including anchor shaft geometry and anchor fin geometry on the hydrodynamic characteristics of anchor are discussed. Based on the obtained findings, some practical design recommendations are given, and a simple semi-empirical method for estimating the falling velocity and inclination angle of dynamically installed anchor subjected to current considering anchor geometric effects is finally proposed, which may benefit the engineering design of dynamically installed anchors.