Theory of the leak-rate of seals

Abstract

Seals are extremely useful devices to prevent fluid leakage. However, the exact mechanism of roughness induced leakage is not well understood. We present a theory of the leak-rate of seals, which is based on percolation theory and a recently developed contact mechanics theory. We study both static and dynamics seals. We present molecular dynamics results which show that when two elastic solids with randomly rough surfaces are squeezed together, as a function of increasing magnification or decreasing squeezing pressure, a non-contact channel will percolate when the (relative) projected contact area, A/A_0, is of order 0.4, in accor dance with percolation theory. We suggest a simple experiment which can be used to test the theory.

12 pages, 19 figures

References in corpus (7)

• On the nature of surface roughness with application to contact mechanics, sealing, rubber friction and adhesion
• Contact mechanics for randomly rough surfaces
• Contact mechanics: relation between interfacial separation and load
• Contact mechanics: contact area and interfacial separation from small contact to full contact
• A multiscale Molecular Dynamics approach to Contact Mechanics
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Cited by in corpus (8)

• Interfacial separation between elastic solids with randomly rough surfaces: comparison of experiment with theory
• Contact mechanics with adhesion: Interfacial separation and contact area
• Significance of Elastic Coupling for Stresses and Leakage in Frictional Contacts
• Contact mechanics of and Reynolds flow through saddle points: On the coalescence of contact patches and the leakage rate through near-critical constrictions
• Computational framework for monolithic coupling for thin fluid flow in contact interfaces
• Revisiting the diffusion equation derivation in Persson's theory of contact
• Fluid leakage in metallic seals
• Theory for diffusive and ballistic air leakage and its application to suction cups