环冷机磁流变液密封研究

考虑到环冷机普遍存在着严重漏风问题，依据磁流变液在外加磁场作用下能呈现出可调的流变特性和可控的屈服应力这一特性，将磁流变液密封技术应用于环冷机，以达到有效解决环冷机漏风的目的。将磁流变液看作Bingham流体，建立磁流变液磁场力和屈服应力数学函数表达式，通过有限元分析，研究非磁性密封槽内的磁流变液在外加磁场力作用下流变和屈服特性，仿真结果表明磁流变液在磁场中具有一定的耐压能力，可平衡环冷机内外压差，起到密封作用，并且非磁性隔板边界处磁流变液屈服应力随密封间隙的增大而减小，同时采用线性拟合方法得到了磁流变液屈服应力表达式以计算非磁性隔板移动所需拉力。在此基础上，通过实验验证了有限元仿真结果的正确性，即采用磁流变液密封的方法可有效地解决环冷机漏风问题。

Research on magnetorheological fluid seal of circular cooler

A new magnetorheological fluid seal technique is developed to deal with the air leakage of circular cooler by considering the serious air leakage of circular cooler based on the adjustable rheological property and controllable yield stress of magnetorheological fluid under external magnetic field.The magnetorheological fluid is regarded as Bingham fluid.Its mathematical functions of magnetic force and yield stress are established.Its flow and yield characteristics in nonmagnetic seal groove under magnetic field is studied using finite element method.The simulation results show that 1. the magnetorheological fluid with good sealing performance presents certain pressure resistance under magnetic field,which can equilibrate the internal-external pressure difference of circular cooler;2. the yield stress of magnetorheological fluid at the boundaries of nonmagnetic separator decreases with the increasing of sealing gap.Meanwhile,the linear fit method is proposed to obtain the yield stress expressions according to which the pulling force values The experimental results also prove the accuracy of numerical results with finite element method,It implies that the air leakage of circular cooler can be solved effectively using the developed technique.