1998 Fiscal Year Final Research Report Summary
Preliminary Investigation of Magnetic Fluid Active Damper
| Project/Area Number |
09555061
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Fluid engineering
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
UENO Kazuyuki Tohoku Univ., Inst.Fluid Sci., Lecturer, 流体科学研究所, 講師 (20250839)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMURA Yusuke Taiho Kogyo, Deputy Research Manager, CE事業部, 技術顧問
OYAMA Tadamasa Tohoku Univ., Inst. Fluid Sci., Research Associate, 流体科学研究所, 助手 (80006189)
KAMIYAMA Shinichi Emeritus Professor of Tohoku Univ., 名誉教授 (80006171)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Magnetic fluid / Active damper / Oscillatory motion / Magnetic field / Fluid resistance / Actuator / Neuro-control |
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| Research Abstract |
The investigations on the following 5 items are conducted.
(1) Construction of an experimental apparatus for the magnetic fluid active damper
The experimental apparatus was constructed to test the suppression of a piston motion immersed in the magnetic fluid in an oscillating container (cylinder) by the control of the applied magnetic field. The piston is connected to the cylinder through a spring-mass system. The cylinder is oscillated by the exciter With frequency off = 2-10 Hz. The suppression force is induced in the magnetic fluid by applying oscillating magnetic field. The natural frequency of the system is designed to be 5Hz when the kerosene based magnetic fluid with 50% mass concentration of magnetite particles is used. As the controlling method, the neural-network controller system is introduced.
(2) Dynamic characteristics of the magnetic fluid active damper
The dynamic characteristics of the active damper are obtained by using the apparatus explained in the above item (1). Neuro
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-controllers (NC) of series and parallel types are designed to control the piston oscillation. The test results show that it is possible to suppress the oscillation of the piston in this system and to give relatively good results by using the parallel type NC compared to the series type NC in the range of the low frequency smaller than the natural frequency of f = 5Hz. By using the magnetic fluid with iron-nitride particles, more efficient characteristics of the magnetic fluid active damper is obtained in comparison with the usual magnetic fluid with the magnetite particles.
(3) Theoretical study of the magnetic fluid active damper
The theoretical study is conducted to understand the suppression mechanism of the oscillation and the necessary conditions of the complete suppression of the piston motion is obtained.
(4) Study of frequency response curve as a magentic fluid actuator
To investigate the dynamic characteristics of the magnetic fluid actuator, the experimental appatatus was slightly changed. The piston motion induced in the stationary magnetic fluid by the applying oscillating magnetic field. The amplitude of the oscillating motion of the piston is obtained as a function of the frequency and the magentic field strength.
(5) Basic study of the oscillation of a flat plate in the magnetic fluid
The flat plate was selected to analyze simply the fluid force acting on the oscillating body. The evaluation of the viscous damping factor and the added mass coefficient was obtained and compared with the experimental results. It is clarified that an increasing rate of a fluid resistance acting on the plate due to the applied magnetic field is large in the tested magnetic fluid with the iron-nitride particles compared to the one with the magnetic particles. Less
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