NUMERICAL SIMULATION ON THE DYNAMIC INSTALLATION OF THE OMNI-MAX ANCHORS IN CLAY USING A FLUID DYNAMIC APPROACH

The OMNI-Max anchors, which are used as foundations for mooring deep-water offshore facilities, are raised recent years for their dynamically installation. ANSYS CFX 17.0 is a computational fluid dynamic (CFD) program, capable of simulating the dynamically installation process of the OMNIMax anchor. In the simulation, soft clay with linearly increasing shear strength is modeled as Eulerian fluid material. The clay is subjected to high shear strain rate during the dynamical installation procedure, hence the H-B model is proposed as it is applicable to a wide range of shear strain rate. Different anchor impact velocity levels are modeled to investigate their effects on the anchor final penetration depths. To improve the anchor impact velocity and final penetration depth, a booster, which is retrievable and renewable, is attached to the tail of the anchor. The results demonstrate that the anchor would achieve deeper penetration depth with the increase in impact velocity. Also the anchor with a booster could reach a deeper penetration depth than that of the single anchor owing to the increase of the anchor total energy.