Leakage Retardation of Static Sealing Via High-Viscosity Medium

Abstract In this article, a novel strategy for the leakage retardation in static sealings has been proposed based on the application of a high-viscosity medium. The sealing performance of oil in a static sealing was systematically investigated to study the effect of gap size, surface roughness, and oil viscosity. Experimental results revealed a significant reduction in the interfacial leakage rate by the application of a high-viscosity oil sealing. The leakage rate was observed to reduce by more than 98% at the gap size of 0 mm as compared with the gap size of 0.2 mm, while an increase in the oil viscosity from 5 cst to 500 cst reduced the leakage rate by 94%. A smooth surface (Sa = 0.718 μm) exhibited an 80% reduction in leakage rate compared to a rough surface (Sa = 5.872 μm). In addition, the failure mechanism of oil sealing was revealed, and the evolution mechanism of the leakage channel under the micro gap was prominently clarified. The results of this investigation are beneficial in the selection and modification of sealing materials and provide theoretical guidance for the study of more complex sealing systems and leakage prediction.