Numerical Investigation On The Hydrodynamic Characteristics Of The OMNI-Max Anchor And Booster

In recent years,the resources of oil and gas in deep sea have gradually become the focus of attention due to the exhaustion of the offshore resources.Considering the harsh environment in the deep sea,the floating platform based on mooring system arises.The OMNI-Max anchor provides a potential alternative to deep water mooring systems due to its efficient and cost-effective anchoring system.The anchor is released at a pre-determined height above the mud-line and gains velocity by converting gravitational potential energy to kinetic energy.And then the anchor penetrates into the seabed under the gravitational potential energy and the kinetic energy obtained during free fall in water.However,the investigations on the anchor mainly focuses on the penetration process of anchor in the seabed and the interaction between the anchor and soil,but the study on the hydrodynamic characteristics of the anchor in free fall stage is relatively few.Therefore,it is of great significance to study the hydrodynamic characteristics of the anchors for the anchor installation.At the same time,the results of previous studies on the anchor demonstrated that the penetration depth of the anchor in the seabed is relatively shallow,indicating that the anchor can be pulled out of the seabed under certain conditions.The anchor penetrates the seabed under the kinetic energy and potential energy,therefore,it is necessary to improve the kinetic energy and potential energy of anchor.In this study,the hydrodynamic characteristics of the anchor were investigated by using the method of computational fluid dynamics(CFD).The booster is designed to improve both the directional stability and terminal velocity of the anchor,such that the anchor can penetrate deeper within the seabed and consequently gain higher bearing capacity.The main research subjects are given as follows:(1)Firstly,the present study is aimed to investigate the drag coefficient,terminal velocity and directional stability of the OMNI-Max anchor at the different attack angles.(2)Then the booster is designed for the OMNI-Max anchor to improve both the directional stability and terminal velocity of the anchor.(3)Finally,an optimized study on the booster geometry was performed to ensure both the directional stability and high terminal velocity of the hybrid anchor at the same time.