气体隔离式磁流体液体旋转密封的耐压能力研究

磁流体旋转密封用于密封液体时,直接接触的磁流体与被密封液体相互作用导致两种流体界面不稳定性发生和增长,耐压能力较差。为提高磁流体对液体介质的密封性能,设计了可避免磁流体与被密封液体直接接触的气体隔离式磁流体密封,对结构中不同密封间隙内的磁场分布进行了仿真分析,得到了该结构各间隙下的最大理论耐压能力,搭建了气体隔离式磁流体密封实验台,在该实验台上进行了磁流体密封液体介质的耐压能力实验。理论与实验研究结果表明,气体隔离式磁流体密封结构对液体介质的耐压能力近似于磁流体密封对气体介质的耐压能力。气体隔离式磁流体密封有效提高了磁流体密封液体的耐压能力。

Sealing Liquid Isolated by Compressed-Gas with Magnetic Fluid:A Methodological Study

We addressed the sealing of the liquid,isolated by compressed-air at an interfacial gap,with magnetic fluid.The original work was the design optimization of isolation gap(hollow-cylinder),effectively confining compressed gas and isolating water from magnetic fluid.First,the impact of the magnetic field on the critical pressure of compressed gas was theoretically analyzed; second,the magnetic field distribution at the optimized gap was simulated with ANSYS software; and finally,the prototyped sealing structure,based on the optimized magnetic field and gas pressure,was evaluated with the lab-built test platform.The results show that the critical pressure of newly-developed water/compressed-gas/magnetic-fluid sealing outperformed that of the water/magnetic-fluid sealing,because the critical pressure was almost equal to that of gas/magnetic-fluid.We suggest that the compressed gas isolation be of some technological interest in sealing of gases with magnetic fluid.