A leakage rate calculation method for rubber O-ring seals based on variable height mixed leakage channel model

Purpose The microscopic topography and macroscopic contact pressure of the sealing surface are critical factors affecting the leakage rate of O-ring seals but are often insufficiently considered in existing calculation models. The purpose of this paper is to establish a leakage rate calculation model for static sealing of rubber O-rings using a combined macro- and micro-scale approach, enabling the convenient and accurate prediction of leakage rates. Design/methodology/approach Drawing on the concept of the classic Roth leakage channel model, and considering the randomness and disorder of the two-dimensional cross-sectional profiles of general rough surfaces, the rough surface topography was approximated in a two-dimensional plane using parametrically arranged triangular peaks, forming a leakage channel model with a mix of triangular and trapezoidal channels. During leakage rate calculations, the non-uniform distribution of contact pressure was mapped to variations in the channel height, thereby comprehensively considering the impact of both microscopic surface topography and the complex distribution of macroscopic contact pressure on the leakage rate. Findings Three sets of leakage rate measurement experiments were designed and conducted. The results show that the average relative error between the calculated values and the experimental measurements is less than 10%, validating the accuracy and effectiveness of the proposed method. Originality/value This study offers an effective method for predicting rubber O-ring leakage, aiding sealing structure design optimization and reliability analysis. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2024-0440/