Effect of the centrifugal and capillary forces on the free surface shape of a magnetic liquid seal

A. N. Vislovich , V. K. Polevikov

Abstract
Results of numerical simulation of an axisymmetrical free surface in a magnetic fluid sealing device for a rotating shaft in the case of a hyperbola shaped concentrator of magnetic field have been presented. The effect of applied magnetic forces and centrifugal forces caused by rotation of the magnetic fluid as well as of magnetic and capillary pressure surface discontinuities have been taken into account. The dependences of the length of the shaft part wetted by magnetic fluid upon the shaft rotation velocity have been obtained for various fluid volumes and contact angles. It has been shown that the application of magnetic fluids with small contact angles leads to essential increase of the reliability of high velocity magnetic fluid sealing devices. The effects of reduction of the heat loss coefficient and of a change of the secondary circulation direction in the seal have been revealed at an increase of the shaft rotation velocity. Figs. 5, refs 9.