Lift Analysis Of Marine Rotary Column Stabilizer And Design Of Roll Reduction At Full Speed Control System

Marine rotary column stabilizer is a full speed anti rolling device,which has great development potential and market application value in the field of ship special auxiliary devices.Because the marine rotary column stabilizer belongs to a new research direction,there is a lack of theoretical analysis and technical guidance in the published data.On the one hand,the lifting force calculation formula is not perfect and cannot provide technical support from the theoretical level.On the other hand,the anti-rolling control system designed for it is not complete and cannot give full play to its performance advantages of anti-rolling at full speed.Therefore,it is a great challenge and urgency to carry out systematic research on its core mechanism and control technology.According to the basic characteristics of Magnus effect,the anti-rolling principle of the rotary column stabilizer is deeply discussed.CFD simulation software FLUENT is used to design the numerical simulation scheme of two-dimensional cylinder.Aiming at the problem that the superposition effect of surface velocity is limited,the action mode of roughness in the wall function is deduced,and the hydrodynamic performance under different roughness heights is studied.As the core theory to guide the follow-up research.From the point of view of practical engineering application,the lifting force calculation formula of the rotary column stabilizer is derived under ideal conditions for the two working modes.The"rotation swing"motion equation is designed,and the swing angle and period are standardized.CFD simulation software FLUENT is used to design the numerical simulation scheme of three-dimensional cylinder and verify its reliability.Under the default roughness of the system,the hydrodynamic performance analysis is carried out for the surface pressure distribution of the rotary column stabilizer and the change of the flow field in the nearby fluid domain.The simulated lift data under the two modes are counted and fitted to improve the lift calculation formula at full speed.It provides theoretical support for the subsequent derivation of the stability mechanism of the spinning column stabilizer and the design of the full speed anti-rolling control system.The stability mechanism of the rotary column stabilizer has been improved,the long peak wave random wave model and the ship roll model have been established,and the roll reduction control model of the rotary column stabilizer has been established.Uncertainty of system recovery torque and damping torque caused by complex and changeable disturbances of external sea conditions,RBF neural network is used to approximate nonlinear functions and sliding mode control is used to suppress disturbances.The RBF neural network sliding mode controller is designed to improve the adaptive rate,and finally the full speed anti-rolling control system of the column stabilizer is designed.Based on the basic parameters of an actual ship and MAGLift ^TMrotating column stabilizer,the SIMULINK simulation platform is built to verify the effectiveness of the system in roll reduction at full speed.The roll angle of the system before and after roll stabilization under different working conditions is analyzed,the roll stabilization efficiency is summarized,and the speed change of the rotary column stabilizer is analyzed.