Influence of power-law fluid on transient performance of liquid film seal based on the time-dependent non-Newtonian dynamic Reynolds equation

Abstract

The effects of lubricant's non-Newtonian property on dynamic characteristics of spiral groove liquid film seal are presented in this paper. The modified dynamic Reynolds equation for non-Newtonian fluid is derived, which is solved simultaneously with the kinematic equation. The transient response to the rotor's axial runout and angular misalignment, such as the axial and angular movement of stator ring, the transient film thickness, are presented for different power-law indexes, as well as the transient performance parameters. The results indicate that the seal has larger film thickness under the lubrication condition with dilatant lubricant while the stator ring has better tracking property operating with shear-thinning lubricant. Overall, the non-Newtonian property should be considered in the design of liquid film seal.