A Numerical Study For Hydrodynamic Characteristics Of The Gravity Installed Anchor

With the gradual advancement of offshore oil and gas resources development from shallow sea to deep sea,deepwater mooring systems are increasingly used in marine engineering.Gravity installed anchors are the latest development of deepwater anchors,which have the comprehensive advantages that other deepwater anchors do not have.According to the engineering background of gravity installed anchor installation,this paper simulates the motion characteristics of the three kinds of gravity anchor during free fall in water,with establishing "static model analysis" and "dynamic model analysis".This paper uses ANSYS Fluent software to establish a "static model analysis" method.This method simplifies the movement of the anchor body in still water by setting the anchor in a fixed position and then causing the fluid in the calculation domain to flow around at a predetermined speed.Through this method,the terminal speed and drag coefficient of different anchor types can be calculated.In this paper,ANSYS Fluent dynamic mesh technology is used to establish a dynamic model analysis method to simulate the dynamic process of free falling of the anchors under the water.Through this method,the detailed changes of the parameters such as the drop height,velocity and drag coefficient of the gravity installed anchor during the falling in the water can be calculated.According to the analysis of the connection between the calculated drop height and the velocity of anchors,the terminal velocity and the efficient installation height of the gravity installed anchors can be proposed.In this paper,the numerical simulation of three gravity penetrating anchors is carried out,and the influence of the structural elements of the anchors on its underwater motion characteristics is analyzed based on the numerical simulation results.The research work in this paper has deepened the understanding of the motion characteristics of gravity installed anchor in water,and can provide reference for the engineering applications of these three forms of gravity installed anchor.