摘要
利用磁天平和电子天平测量了不同电流和高度下磁性液体的表观密度。使用霍尔传感器测量不同电流下轴线上的磁场强度,通过origin软件对磁场强度拟合并求偏导,得到不同电流下轴线上的磁场梯度分布曲线。根据磁性液体的Bernoulli方程推导了磁性液体表观密度的表达式,磁性液体的表观密度由磁性液体的固有密度、磁化强度以及外加磁场及磁场梯度决定。无磁场作用时,磁性液体密度各处相等,说明磁性液体中的纳米磁性颗粒均匀分散在载液中;有外磁场作用时,随着外加磁场增强,磁场梯度也逐渐增强,导致磁性液体中悬浮的磁性颗粒移动到磁场及磁场梯度增强的位置,使得该处磁性液体的表观密度增加,理论结果与实验结果一致。
Magnetic fluid＇s apparent density was carried out along the z axis for different currents by magnetic balance and electronic balance. Magnetic field was measured along the z axis for different currents by Hall sensor and magnetic field distribution was fitted and was differentiated in order to be magnetic field gradient distribution by the origin software. The formula for magnetic fluid＇s apparent density was derived based on Bernoulli＇s equation of magnetic fluid. Magnetic fluid＇s apparent density was controlled by the intrinsic density, magnetization, the applied magnetic field and magnetic field gradient. In the absence of magnetic fluid, Magnetic fluid＇s apparent density was equal everywhere and magnetic particles are randomly suspended in a carrier fluid. When magnetic field and magnetic field gradient gather strengthen in applied transverse magnetic field, magnetic particles would move to the location of the greater magnetic field and the magnetic field gradient and it would lead to the increase of magnetic fluid＇s apparent density. The theoretical results coincide with the experimental results.
出处
《实验技术与管理》
CAS
北大核心
2013年第6期28-30,共3页
Experimental Technology and Management
基金
国家自然科学基金项目(51077006)
关键词
磁性液体
表观密度
磁天平
magnetic fluid
apparent density
magnetic balance
