| Excellent seakeeping performance is the basis of safe operation of ships.From 1890 to now,there have been more than hundreds of anti rolling devices.However,due to the limitation of the industrial technology at that time,only fin stabilizer,rudder stabilizer,anti rolling tank,gyroscope and so on are commonly used.With the development of industrial technology,the research and development of new materials and new equipment can provide effective assistance and support for the development of new anti rolling devices.Some foreign anti rolling equipment companies have developed a new type of anti rolling device and applied it to the real ship.The principle of the device is the rotating and swinging cylinder anti rolling device based on Magnus effect.The anti rolling device can realize full speed ship rolling reduction,and has the characteristics of small installation space and low manufacturing and maintenance cost.The corresponding research work of domestic scholars in this area is still in the preliminary stage of exploration.Therefore,in order to solve the hydrodynamic problem of the cylinder rotating and swinging,the mechanism of the coupling hydrodynamic effect is explored.In this paper,the hydrodynamic performance of Magnus effect rotating cylinder and swinging rotating cylinder are studied by experimental test and numerical simulation.This paper first designs the test device for rotating cylinder and swing rotating cylinder,and introduces the test scheme of rotating cylinder and swing rotating cylinder,including the research target model size,test conditions,physical quantities to be studied,etc.,so as to lay the foundation for the next rotating cylinder and swing rotating cylinder test.The hydrodynamic performance of a rotating cylinder and a swinging rotating cylinder is studied by model test and PIV test in a circulating water tank.At high velocity,the influence of Reynolds number,aspect ratio,speed ratio and other parameters on the hydrodynamic performance of the rotating cylinder is analyzed;at zero velocity,the influence of different swing angle,swing speed and swing ratio on the lift and tail flow field of the rotating cylinder is analyzed;at low speed,the influence of incoming flow speed on the lift and tail flow field of the rotating cylinder is analyzed,and the downstream and counter current swing are analyzed The same or different dynamic velocity is the change of hydrodynamic performance of the oscillating rotating cylinder.It can provide theoretical support for the research of anti rolling device based on Magnus effect.Based on the large eddy simulation method,the numerical simulation of rotating cylinder is carried out.The effects of length diameter ratio(variable diameter,variable length),Reynolds number and speed ratio on the lift and drag of rotating cylinder are mainly discussed,and the hydrodynamic performance of rotating cylinder is analyzed from the angle of flow field change at the tail of rotating cylinder.The hydrodynamic performance of the oscillating rotating cylinder is studied by numerical simulation.At zero speed,the influence of the swing angle,swing speed and swing ratio of the cylinder on the hydrodynamic performance of the base oscillating rotating cylinder is analyzed.The influence of reversing and non reversing rotation direction on the hydrodynamic performance of the oscillating rotating cylinder at the critical angle is compared.The flow field changes at different sections of the oscillating rotating cylinder are studied Hydrodynamic performance of rotating cylinder.At low flow velocity,the lift and drag performance of a rotating cylinder with different incoming flow velocity,swing angle,swing speed and swing ratio are compared,and the lift and drag and the change of the flow field at the tail are analyzed when the cylinder swings downstream and upstream.Finally,the accuracy of this study is verified by comparing the experimental and numerical simulation results,which lays a foundation for the subsequent application of Magnus anti rolling device. |
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