Lorentz force velocimetry(LFV) is a noncontact technique for measuring electrically conducting fluids based on the principle of electromagnetic induction. This work aims to answer the open and essential question of wh...Lorentz force velocimetry(LFV) is a noncontact technique for measuring electrically conducting fluids based on the principle of electromagnetic induction. This work aims to answer the open and essential question of whether LFV can work properly under a surrounding external magnetic field(ExMF). Two types of Ex MFs with different magnetic intensities were examined: a magnetic field with a typical order of 0.4 T generated by a permanent magnet(PM) and another generated by an electromagnet(EM) on the order of 2 T. Two forces, including the magnetostatic force between the Ex MF and PM in the LFV, and the Lorentz force generated by the PM in LFV were measured and analyzed in the experiment. In addition,Ex MFs of varying strengths were added to the LFV, and the location of the LFV device in the iron cores of the EM was considered. The experimental outcomes demonstrate that it is possible for a LFV device to operate normally under a moderate Ex MF. However, the magnetostatic force will account for a high proportion of the measured force,thus inhibiting the normal LFV operation, if the Ex MF is too high.展开更多
A new electromagnetic stirring technique that is driven by hydrodynamic forces was presented. This technique offers the following advantages. First,the stirrer can be immersed in the liquid metal,thereby significantly...A new electromagnetic stirring technique that is driven by hydrodynamic forces was presented. This technique offers the following advantages. First,the stirrer can be immersed in the liquid metal,thereby significantly increasing the penetration depth of the electromagnetic forces and significantly improving the stirring efficiency; thus,this technique is particularly suitable for large-scale liquid metal. Second,under certain conditions,this technique can overcome difficulties that are encountered with traditional stirrers,such as accessing regions that are difficult to reach in working spaces with complex or narrow shapes. This stirrer also has a simpler structure than a traditional stirrer; thus,the design can be easily modified,and no external power supply is required. An experimental prototype was also presented for controlling the fluid flow rate,thereby controlling the electromagnetic force and velocity field of the driven liquid metal. The velocity distribution in a liquid Ga In Sn alloy under fluid-driven electromagnetic stirring was quantitatively measured using ultrasonic Doppler velocimetry（ UDV）. The primary results show that a remarkable velocity field has been achieved and that fluid-driven electromagnetic stirring is an effective means of stirring liquid metal. Finally,the potential applications of this technique in industry,along with key challenges,were discussed.展开更多
基金supported by the National Natural Science Foundation of China(No.51374190)the Major Equipment Fund of Chinese Academy of Sciences(No.YZ201567)
文摘Lorentz force velocimetry(LFV) is a noncontact technique for measuring electrically conducting fluids based on the principle of electromagnetic induction. This work aims to answer the open and essential question of whether LFV can work properly under a surrounding external magnetic field(ExMF). Two types of Ex MFs with different magnetic intensities were examined: a magnetic field with a typical order of 0.4 T generated by a permanent magnet(PM) and another generated by an electromagnet(EM) on the order of 2 T. Two forces, including the magnetostatic force between the Ex MF and PM in the LFV, and the Lorentz force generated by the PM in LFV were measured and analyzed in the experiment. In addition,Ex MFs of varying strengths were added to the LFV, and the location of the LFV device in the iron cores of the EM was considered. The experimental outcomes demonstrate that it is possible for a LFV device to operate normally under a moderate Ex MF. However, the magnetostatic force will account for a high proportion of the measured force,thus inhibiting the normal LFV operation, if the Ex MF is too high.
基金Item Sponsored by the Program of "One Hundred Talented People"of the Chinese Academy of Sciences(111800M105)Chinese Academy Sciences Funding(04078400)
文摘A new electromagnetic stirring technique that is driven by hydrodynamic forces was presented. This technique offers the following advantages. First,the stirrer can be immersed in the liquid metal,thereby significantly increasing the penetration depth of the electromagnetic forces and significantly improving the stirring efficiency; thus,this technique is particularly suitable for large-scale liquid metal. Second,under certain conditions,this technique can overcome difficulties that are encountered with traditional stirrers,such as accessing regions that are difficult to reach in working spaces with complex or narrow shapes. This stirrer also has a simpler structure than a traditional stirrer; thus,the design can be easily modified,and no external power supply is required. An experimental prototype was also presented for controlling the fluid flow rate,thereby controlling the electromagnetic force and velocity field of the driven liquid metal. The velocity distribution in a liquid Ga In Sn alloy under fluid-driven electromagnetic stirring was quantitatively measured using ultrasonic Doppler velocimetry（ UDV）. The primary results show that a remarkable velocity field has been achieved and that fluid-driven electromagnetic stirring is an effective means of stirring liquid metal. Finally,the potential applications of this technique in industry,along with key challenges,were discussed.
