Control of Thermal Convection in Water by Strong Gradient Magnetic Fields
Control of Thermal Convection in Water by Strong Gradient Magnetic Fields
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DOI：
10.1143/jjap.42.l715
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发表时间：
2003-06
影响因子：
1.5
通讯作者：
I. Mogi;C. Umeki;Kohki Takahashi;S. Awaji;Kazuo Watanabe;M. Motokawa
中科院分区：
文献类型：
--
作者：
I. Mogi;C. Umeki;Kohki Takahashi;S. Awaji;Kazuo Watanabe;M. Motokawa
利用热致变色液晶片在强梯度磁场下直观观察了水中的传热过程。向上的热对流显着抑制的磁力，然而，它仍然在很小的程度上，即使在磁悬浮条件下的梯度场B（dB/dz）=1360 T2·m-1。在35-40°C的较强梯度磁场B（dB/dz）=2880 T ~ 2·m ~（-1）下，实现了无对流的热传导状态，而在40-45°C的相同梯度磁场下，观察到了向下的磁对流。水的磁化率的温度依赖性是负责在梯度场的对流行为。
Heat transfer in water was visually observed using a liquid-crystal sheet with thermochromism under strong gradient magnetic fields. Upward thermal convection was significantly suppressed by the magnetic force, however, it remained to a small extent even under magnetic levitation conditions with a gradient field of B(dB/dz)=1360 T2·m-1. A thermal conduction state without convection was realized under a stronger gradient field of B(dB/dz)=2880 T2·m-1 at 35–40°C, and surprisingly the downward magnetic convection was observed under the same field at 40–45°C. The temperature dependence of the magnetic susceptibility of water is responsible for the convection behavior in the gradient fields.