Research On U-tube Anti-rolling Tank And Test Rolling Table Experimentation

The anti-rolling tank is one of the most popular used stabilizing equipments,and it fits for ships working at zero speed or low speed such as passenger and train ferry,roll-off vessel,research and exploration vessel and so on in particular. It can be classified as U-tube tank stabilizer and flume anti-rolling tank according to structural configuration,and the former has three types,namely passive,active control and controlled passive tank in terms of the control mode. Test rolling table is an analogue equipment,which simulates the motions of a ship disturbed by the wave force,and it serves as the bench simulated ship motions for performance test of the anti-rolling tank.The paper is based on the item the anti-rolling tank test setup among the school 211 key construction projects. Tank system design,control method of tank and correlation technique of simulation of the test rolling table are investigated mainly.The paper introduces the classifications and characteristic of the anti-rolling tank and summarizes the state-of-the-art of the anti-rolling tank at home and abroad. In addition,the development of rolling analog table for performance test of the tank model is expatiated.According to the Lagrange dynamics equation of motion,a mathematical model of the ship-controlled passive anti-rolling tank system is developed. The author considers the swaying disturbance's power for the first time when the draught of a ship is not equal to the height of gravitational center of the ship in analyzing exciting force affecting the performance of tank. At the same time,it gave frequency domain and time domain solutions of system equations about two motions on pure rolling and rolling coupled swaying of the ship.Based on analyzing the control principle of the anti-rolling tank,the optimal control of controlled passive tank is devised according to the principle of optimal control,and the implementation approach presented. The author also studies the controller design of the activated tank,presents the technique of enumerating tankactive force,and simulates the three kinds of tank system.Design procedure of U-shaped anti-rolling tank system is established,and program of scale design for tank is summarized,and an innovation selecting the natural frequency of controlled passive anti-rolling tank is put forward according to variation range of wave frequency,the natural frequency of rolling of a ship and other influencing factors,and causes of formation of tank damping and motion state of water in tank are studied,calculation formula of the U-tube tank damping and design method of tank damping configuration are given,and the influence of tank vertical location within the ship on ship parameters,stabilization performance of tank and water motion in tank is studied. The performance test of tank model indicates that the theoretical analysis is correct.The test rolling table that can simulate two-degree-of-freedom motions of a ship,namely rolling and swaying,is developed,which makes up for shortage of test rolling bench used for performance test of tank. A detailed study has been made of the main problems of test rolling analog table simulation,including simulation of wave disturbance force/moment and attenuation force/moment of the ship. Moreover,the adjusting method of test rolling analog table is given.The monitoring system of anti-rolling tank model performance takes charge of control and regular service of anti-rolling tank. The design of hardware and software for tank control system is developed,and system software is used for tank control,data acquisition,and processing test results.In the end,test results of rolling table for anti-rolling tank model are presented. The test results indicated that test rolling table can simulate ship rolling motions on the wave and passive U-tube tank designed achieves stabilization effects to a certain extent. Test result is in accord with estimated value for the natural frequency of tank. Forced oscillation test results of rolling table show that the theoretical anal...