Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants |
|Research Institution||Tohoku University |
KAMIYAMA Shinichi Institute of Fluid Science, Tohoku University, 流体科学研究所, 教授 (80006171)
CHANTRELL R.w. Dept.of Phys., Keele University, 物理科, 教授
O'GRADY K. Dept.of Elect.Engng., Univ.Coll.of North Wales, 電気工学科, リーダー
POPPLEWELL J. Dept.of Elect.Engng., Univ.Coll.of North Wales, 電気工学科, リーダー
CHARLES S.w. Dept.of Chemistry, Univ.Coll.of North Wales, 化学科, リーダー
NAKATANI I. National Res.Inst.for Metal, 金属材料技術研究所, 室長
佐藤 明 千葉大学, 工学部, 助手 (50211941)
NAKATSUKA K. Faculty of Engng., Tohoku University, 工学部, 教授 (60005345)
山根 隆一郎 東京工業大学, 工学部, 教授 (50016424)
小池 和雄 東北学院大学, 工学部, 助教授 (20108575)
棚橋 隆彦 慶應義塾大学, 理工学部, 教授 (70051638)
SATOH A. Dept.of Mech.Engng., Chiba University
YAMANE R. Dept.of Mech.Engng., Tokyo Inst.of Tech.
TANAHASHI T. Dept.of Mech.Engng., Keio University
KOIKE K. Dept.of Mech.Engng., Tohokugakuin University
|Project Period (FY)
1993 – 1994
Completed (Fiscal Year 1994)
|Budget Amount *help
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥2,000,000 (Direct Cost: ¥2,000,000)
|Keywords||Magnetic Fluid / Magnetic Control / Fine Particle / Pipe Flow / Damper / Actuator / Aggromeration|
(1) Preparation and Characterisation of Magnetic Fluids
Magnetic and sedimentometry measurements of the magnetic fluids prepared in Japan (commercial fluids and Fe_3N fluid) were carried out and compared with ones prepared at Bangor by the thermal decomposition of cobalt octacarbonyl. Also, magnetic properties of Co magnetic fluid and chemical composition, magnetic mean diameter were measured by using high resolution electron micrograph and microbeam electron diffraction technique at National Res.Inst.for Metal, Tsukuba.
(2) Theoretical Approach for Magnetic Particles' Aggregation
Since the diameter of particles is typically about 10nm, the simple theory that the particles combine with each other to form chainlike clusters cannot be applied in explaining the formations of the thick chainlike clusters which are observable even with a microscope. A secondary particle concept can explain very well the formation of the thick chainlike clusters. We attempted to capture the thick chainlike clus
ters, like those observed experimentally, by means of the 3D cluster-moving Monte Carlo method. Specifically, the influence of the strengths of magnetic particle-particle and particle-field interactions on the aggregate structures are clarified. Besides, the internal structures themselves are discussed by means of pair correlation functions.
(3) Flow Characteristics of Magnetic Fluid and Applications
As the basic studies of hydrodynamics of magnetic fluids, various pipe flow problems were investigated, that is, the effect of magnetic field on the characteristics of (a) a gas-liquid two-phase flow and (b) oscillatory flow.
In the oscillatory pipe flow problems, theoreticall analysis was conducted to clarify the effect of magnetic field on the fluctuating pressure in the flow by taking into account the particle aggregates and particle number density distribution in nonuniform magnetic field which showed a reasonable agreement with the experimental results.
In the investigation of boiling two-phase flow, the effect of magnetic field on the void and pressure distributions was experimentally clarified by using ultrasonic wave echo technique for visualization of vapor bubble produced in the magnetic fluid.
As the basic studies of applications of magnetic fluids, the flow characteristics of magnetic fluid in viscous dampers, active dampers, actuators and energy conversion system were clarified. Less