Hydrodynamic Characteristic Analysis Of Low Speed Fin And Drive Control Technology Research

At high or medium speed (conditions), about 90% roll reduction is achieved by fin stabilizer, but on the condition of low speed or anchored, it works poorly. The key factor is that the flow speed of water past the surface of fin stabilizer approach to zero. When the speed is low or zero then the stabilizing moment becomes very small and at zero speed vanishes altogether. For the ship that needs to accomplish the project in the fixed sea area as well as the large yachts sailing at low speed or on drift condition, it had to equip the vessel with anti-roll tank in order to ensure the safety of engineering and the health of mariner. The cost of equipped both fin stabilizer and anti-roll tank is expensive as well as complex matching device. Therefore, the researcher spent much time and energy on designing zero speed stabilization system. Though some foreign company and institutions have already developed new stabilizing (zero speed) system for zero speed, but the domestic market still remain in the stage of research and development.Based on the intensive research of the background and for the purpose of practical, this article makes a depth simulations research on the hydrodynamic characteristic of the quadrilateral fin.The main research content covers the follow aspects: firstly, the present situation of domestic and overseas was summarized and the result of several model tests was analysis.Secondly, the operating principle both on high or medium and low forward speed or drift was elaborated. Then, the force compute formula was derived combined with the theory. Once more, we established the three-dimensional numerical value model based on the geometry parameter of quadrilateral fin. We make comparison between quadrilateral fin and traditional fin on the hydrodynamic force. And also we carried out a great quantity simulation with the fin swinging from maximum angle on one side to maximum angle on the opposite side, came up with optimizing operating principle and summarized the force function of the fin in the way of analysis simulation data. Take the profile of quadrilateral fin into consideration, both static and dynamic hydrodynamic characteristic of fin with plates were performed.Finally, the paper deliberated the design principle of zero speed fin and illustrate it simple with an specific simulation result. In the final part, using the long random wave as the outside disturb and building the whole control simulation system by means of SIMULINK.Setting up different state of the sea and contrasted the roll reduction of the whole system.