均匀磁场强化磁性液体导热系数实验研究

摘要

将封有聚α-烯烃合成油基磁性液体的两玻璃管放置于磁场中,为消除磁场力、重力所引起的磁性液体自然对流的影响,消除端部效应,研制了磁性液体在均匀磁场中瞬态双热线导热系数的实验测量系统.实验测量了均匀磁场对不同体积浓度的磁性液体导热系数的影响.结果显示,均匀磁场显著强化磁性液体的导热系数,其导热系数随磁场强度的增加而近似线性增加,且体积浓度越大增加量越大.%Polymeric α-olefin based magnetic fluids sealed in two glass tubes were placed in external magnetic field. To eliminate the end effect and the natural convection induced by magnetic and gravity force, the transient hot-wire (THW) instrument was developed for accurate measurements of thermal conductivity of magnetic fluids.Effects of external magnetic field on the thermal conductivity of magnetic fluids with different volume fraction of suspended magnetic particles were measured. Results indicated that the thermal conductivity of the magnetic fluid increases greatly with applied field. The conductivity increases almost linearly with the strength of the magnetic field,and the higher the particle concentration, the more increment of thermal conductivity.