磁性液体动静密封时界面形状仿真分析

Simulation analysis of interface shape in dynamic and static sealing of magnetic liquid

对磁性液体动静密封时界面形状的研究是解决密封液体界面不稳定的关键。由于磁性液体密封装置材料的限制,利用试验的方法观察密封时的界面形状存在一定困难。基于数值计算和理论推导相结合的方式,对磁性液体动静密封时的界面形状进行研究。研究表明,静密封时,密封压力和密封间隙处磁感应强度分布是决定磁性液体界面形状的主要因素,当外界压力为理论密封压力最大值的50%时,界面形状呈现双曲线函数轮廓,有利于界面稳定;当外界压力为理论密封压力最大值的75%时,界面形状存在凸起,严重影响界面稳定性;当密封压差为理论密封压力最大值时,界面形状呈现S型,界面稳定性较好。动密封时,界面形状受转速、轴径、外界压力、磁感应强度分布共同影响,对动密封时界面形状推导了理论公式。

The study of interface shape is the key to solve the instability of sealing liquid interface.Due to the limitation of the material of magnetic liquid sealing device,it is difficult to observe the shape of sealing interface by experimental method.Based on the combination of numerical calculation and theoretical derivation,the interface shape of magnetic liquid in dynamic and static sealing is studied.Research shows that,sealing pressure and magnetic induction intensity distribution at sealing gap are the main factors that determine the shape of magnetic liquid interface in static sealing.When the external pressure is 50%of the maximum theoretical sealing pressure,the shape of the interface is hyperbolic,which is conducive to the stability of the interface.When the external pressure is 75%of the maximum theoretical sealing pressure,the interface shape is convex,which seriously affects the interface stability.When the sealing pressure difference is the maximum theoretical sealing pressure,the interface shape is S-shaped and the interface stability is good.In dynamic sealing,the interface shape is affected by rotational speed,axis diameter,external pressure and magnetic induction intensity distribution.The theoretical formula of interface shape in dynamic seal is derived.