Investigation of the heat transfer characteristics of Galinstan liquid metal driven by electromagnetism

Galinstan liquid metal is considered a promising coolant for the spindle shaft of motorized spindles due to its advantages of non-toxicity, high stability, and high thermal conductivity. Moreover, Galinstan has preferable electromagnetic drive characteristics, which aid in avoiding the problem of high-pressure dynamic seals. In addition, it has a density close to that of steel, which helps avoid imbalances. This work presents a shaft cooling structure based on Galinstan and driven by electromagnetism. An investigation of the heat transfer character-istics of Galinstan with or without the heating area in a vertical magnetic field is carried out. The results showed that Galinstan can be employed to flow in a copper loop with an inner diameter of 8 mm with a magnetic field intensity of 0.15 T and a driving current of 4 A. With the increase in heating power, the heat transfer performance of Galinstan driven by electromagnetism in the heating area, exhibits little change. On the other hand, the performance increases significantly with the increase in the driving current. Also, the magnetohydrodynamics (MHD) effect created by the magnetic field is not capable of improving the heat transfer performance signifi-cantly. This is because the MHD effect increases the flow resistance and reduces the overall flow velocity.

Automated summary

This study presents a shaft cooling structure driven by electromagnetism, using Galinstan as the coolant, which has the advantages of non-toxicity, high stability, and high thermal conductivity. The results show that the heat transfer performance of Galinstan can be improved by increasing the driving current, while the magnetohydrodynamics (MHD) effect created by the magnetic field has little effect on the heat transfer performance.