High Functionalbility of Magnetic Fluid and its Application

对高功能化磁性液体的基本性质(主要是磁性和流变性)、流体流动问题及其应用进行了研究。组织了两次研讨会，以制定日本和法国之间的合作研究项目。主要讨论了以下几个方面的内容：(1)高性能磁性液体的合成及物性研究磁性液体作为智能材料的改进。通过控制细微磁性颗粒的表面改性和通过制造复杂的磁性液体来进行流体。阐明了这些高功能化磁性液体的物理性质。特别是随着新的测量技术的发展，对超细磁性粒子的磁性和磁性液体的光学性质(Soret效应)进行了研究。磁流体的流体力学作为管流问题，阐明了非均匀磁场对沸腾两相流和振荡流的影响。阐明了磁流体液滴的磁不稳定性和界面的粘性不稳定性(类似于Saffman-Taylor条纹)。(3)应用为获得这些应用机器和设备的高性能，开展了磁流体主动阻尼器、热管和能量转换系统的基础研究。此外，这种磁性液体的医学应用也在取得进展。

The basic properties (mainly, magnetic and rheological properties), fluid flow problems of the magnetic fluid showing a high functionability and its applications were investigated. Two seminars were organized to develop collaborative research projects between Japan and France. The following topics were discussed in the seminars.(1) Synthesis and physical properties of the magnetic fluid with the high functionabilityImprovement of the magnetic fluid as an intelligent. fluid has been conducted by controlling a surface modification of fine magnetic particles and by making the complex magnetic fluid. The physical properties of these magnetic fluids with the high functionability were clarified. In paticular, the magnetic properties of the ultra-fine magnetic particles and the optical properties of the magnetic fluid (Soret effect) were conducted with the development of new measuring techniques. Liquid-metal based magnetic fluid were prepared.(2) Hydrodynamics of the magnetic fluidAs pipe flow problems, the effect of a nonuniform magnetic field on the boiling two-phase flow and the oscillatory flow was clarified. Also, the magnetic instability of the magnetic fluid drop and the viscous instability of the interface (analogeous to the Saffman-Taylor fringer) were clarified.(3) ApplicationsThe basic studies of the development of a magnetic fluid active damper, a heat pipe and a energy conversion system were conducted to get the high performance of these applied machines and equipments. Also, a medical application of the magnetic fluid is progressing.