非均匀磁场中磁流体热磁对流的实验研究

建立了测量非均匀磁场条件下圆柱腔体内磁流体热磁对流特性的实验系统,实验结果显示,磁流体热磁对流特性受磁场强度、温差以及磁场梯度方向与温度梯度方向之间关系的控制,当磁场梯度方向与温度梯度方向一致时,外加磁场强化了磁流体的热磁对流过程,且随着磁场强度和温差的增大,热磁对流强度加强。当磁场梯度方向、温度梯度方向以及重力方向三者相同时,磁流体的热磁对流强度最剧烈。

EXPERIMENTAL INVESTIGATION ON THERMOMAGNETIC CONVECTION OF MAGNETIC FLUID IN THE PRESENCE OF A NON-UNIFORM MAGNETIC FIELD

An experimental system was built to study thermomagnetic convection of magnetic fluid in a column enclosure with the presence of a non-uniform magnetic field. The experimental results indicate that the thermomagnetic convection of the magnetic fluid is dominated by the intensity values of the external magnetic field, the temperature gradient, and the synergetic relation between the orientations of these fields. Thermomagnetic convection may arise, and the Nusselt number increases in the case that both the orientations of the temperature gradient and the external magnetic field are parallel (the same direction of the gravity). The Nusselt number increases with increases in the strength of the applied magnetic field and in the temperature gradient.