Natural Convection of a Magnetic Fluid under the Magnetic Field

磁场下磁流体的自然对流

• 批准号: 01550157
• 负责人: TANAHASHI Takahiko
• 金额: $ 1.15万
• 依托单位: KEIO University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550157/
• 关键词: Magnetic fluid; Natural Convection; Magnetic Field Control; Heat Transfer Enhancement; Numerical Analysis; Finite Element Method; Constitutive Equation; Sloshing; 非ニュ-トン流体; 極性流体; 熱対流; マイクロ・ポ-ラ流体

Natural convection of a magnetic fluid was studied experimentally and numerically for three models which was a cubic cavity, a cubic cavity which had a horizontal cylinder and the coaxial cylinders. Magnetic fields were applied in various directions by permanent magnets. The thermosensitive liquid crystal sheet was utilized in order to visualize wall-temperature distributions. Several kinds of experiment were carried out in order to clarify the influence of direction and strength of magnetic fields on the natural convection. Numerical Simulations by finite element method were used to show velocity and temperature fields in the magnetic fluid. Boussininesq approximation was used and the induced magnetic field caused by a motion of magnetic particle was ignored in the calculation. Temperature distributions and velocity field in magnetic fluid were observed in detail by the calculation results. As these results it became known that the natural convection of a magnetic fluid was controlled … More by the intensity and direction of the magnetic fields.To investigate the thermal properties of magnetic fluids, we introduced a new way of determining constitutive equations of magnetic fluids. That is the method which is a combination of the theory of integrity bases and the principle of maximal dissipation rate based on the thermodynamical discussions. The basic equations, which derived by this method, satisfy the principle of material frame indifference. Furthermore, they express viscoelastic effect internal freedom, conducting effect, and nonlinear effect simultaneously Using this method, the basic equations of both nonconducting and conducting nonpolar magnetic fluids were given.Some dynamic behavior of a magnetic fluid in a container were experimentally examined. Experiments were carried out for rectangular, cylindrical and spherical containers respectively. These containers were laterally oscillated. The vertical non-uniform magnetic field was applied by permanent magnets which were fitted underneath the container. It was found that harmonic wave motion, swirling waves and flow pattern of surface waves were influenced by the magnetic fields. The resonant frequency of the fluid-container system moved toward high frequency region with the magnetic field intensity. This behavior was also studied by the linear approximate theory. Theoretical results were qualitatively in good agreement with experimental results. Less

对磁流体在立方腔体、水平圆柱体和同轴圆柱体三种模型下的自然对流进行了实验和数值模拟研究。通过永磁体在各个方向上施加磁场。利用热敏液晶片，以可视化壁温分布。为了阐明磁场方向和强度对自然对流的影响，进行了多种实验。采用有限元方法对磁流体的速度场和温度场进行了数值模拟。计算中采用了Boussininesq近似，忽略了磁性粒子运动引起的感应磁场。计算结果详细观察了磁流体内部的温度场和速度场。根据这些结果，人们知道磁性流体的自然对流是受控的 ...更多信息 为了研究磁流体的热物性，提出了一种确定磁流体本构方程的新方法。在此基础上，提出了一种将完整基理论与最大耗散率原理相结合的方法。用这种方法导出的基本方程满足物质坐标无差异原理。利用该方法，给出了非导电和导电非极性磁流体的基本方程，并对磁流体在容器中的动力学行为进行了实验研究。分别对矩形、圆柱形和球形容器进行了实验。这些容器横向摆动。垂直非均匀磁场由安装在容器下方的永磁体施加。结果表明，磁场对表面波的谐波运动、旋转波和流型都有影响。流体-容器系统的共振频率随磁场强度的增大而向高频区移动。用线性近似理论研究了这种行为。理论结果与实验结果定性吻合良好。少

项目成果

棚橋 隆彦: "連続体の力学(4)" 理工図書, 350 (1989)

Takahiko Tanahashi：“连续体力学（4）”Riko Tosho，350（1989）

T. Sato, A. Saito and T. Tanahashi: ""Numerical Analysis of Natural Convection of an Electrically Conducting Fluid under Magnetic Field Using the GSMAC Finite-Element Method"" Trans. Jap. Soc. Mech. Eng.Vol. 56, No. 526, B. 1571-1578 (1990)

T. Sato、A. Saito 和 T. Tanahashi：“使用 GMAC 有限元方法对磁场下导电流体的自然对流进行数值分析”Trans。

佐藤 敏浩・斉藤 敦・棚橋 隆彦: "GSMAC有限窒素法による磁場下の電磁流体の自然対流の解析" 日本機械学会論文集(B編). 56. 1571-1578 (1990)

Toshihiro Sato、Atsushi Saito、Takahiko Tanahashi：“使用 GMAC 有限氮法分析磁场下磁流体动力学中的自然对流”日本机械工程师学会会刊（编辑 B）（1990 年）。

H.Kikura,A.Saito,T.Sawada and T.Tamahashi: "Natual Convection of Magnetie Fluid under Magnetic Fields" Pro ceedings of the Second KSMEーJSME Fluid Engineering Conference,Seoll Korea. 2. 128-133 (1990)

H.Kikura、A.Saito、T.Sawada 和 T.Tamahashi：“磁场下磁流体的自然对流”第二届 KSME-JSME 流体工程会议论文集，韩国 Seoll 2. 128-133 (1990)。

佐藤 敏浩・斉藤 敦・棚橋 隆彦: "GSMAC有限要素法による磁場下の電磁流体の自然対流の解析" 日本機械学会論文集(B編). 56. 1571-1578 (1990)

Toshihiro Sato、Atsushi Saito、Takahiko Tanahashi：“使用 GMAC 有限元法分析磁场下磁流体动力学中的自然对流”日本机械工程师学会会刊（编辑 B）（1990 年）。