Study on working mechanism and performance of deep groove seal at high temperature and high speed in mixed lubrication

The deep groove seal is a kind of mechanical seal with millimeter depth grooves on the end face of the sealing ring, widely used in aviation and nuclear fields. However, its working mechanism and sealing performance are still unclear. In this research, a fluid-solid-thermal coupling numerical analysis model at high temperature and high speed in mixed lubrication is established to solve these problems. Mechanism analysis indicates that deep grooves cause circumferential waviness of micron level on the end face, strongly affecting the sealing performance. A quantitative characterization method is proposed, solving the characteristic parameters and analytical expression of deep groove seal waviness, so that the deep groove seal can be approximately equivalent to the waviness seal and be explained by the law of the waviness seal. The sealing performance can be controlled through the design of groove parameters. The results have been verified by the experiment. The fluid-solid-thermal coupling model and characterization method of equivalent waviness parameters for the deep groove seal proposed in this article provide a theoretical basis for further study of the mechanism and performance of the deep groove seal.