Leak rate of seals: Effective-medium theory and comparison with experiment

Abstract

Seals are extremely useful devices to prevent fluid leakage. We present an effective-medium theory of the leak rate of rubber seals, which is based on a recently developed contact mechanics theory. We compare the theory with experimental results for seals consisting of silicon rubber in contact with sandpaper and sand-blasted PMMA surfaces.

Lubrication in soft rough contacts: A novel homogenized approach. Part I - Theory

“…As an example in the static case, the hydraulic conductivity of a contact interface, which is of utmost importance for industrial applications (e.g. sealants, tires) as well as for life science (dewetting at soft rough interfaces), has been recently modeled in the case of isotropic surfaces recurring to percolation theory arguments, [16][17][18] which are in good agreement with experiments. 19 Experimental observations of sliding contacts made with optical interferometry (see e.g.…”

“…Substituting Eqn (17) in Eqn (15) we find that the transform of the separation fluctuation (induced by the fluid action) can be written as:…”

“…We observe that at a z 0.34 the fluid flow area vanishes, although free voids are still present at the interface. This interesting effect, which has so far been investigated only for static seals, [16][17][18]46 is determined by the occurrence of two-dimensional contact geometries at the interface, which behave like solid walls that prevent fluid flow through the voids. Even for small percentages of the contact area (see Fig.…”

Permeability, Strength and Filtration Performance for Uncoated and Titania-Coated Clay Wastewater Filters

“…It is analogous to current flow in electricity: I = σA∆V/∆L and where κ/µ in the fluid plays a role similar to σ in electrical calculations and we may use the Effective Medium Approximation (EMA) of conductivity to explain the permeability of porous materials (Mikrajuddin and Khairurrijal, 2009;Lorenz and Persson, 2010).…”

The Influence of the Fractal Dimension of Rough Surfaces on the Adhesion of Elastic Materials

“…Theoretical and experimental research on contact mechanics between rough surfaces is stimulated by the crucial role that this topic plays in a large number of engineering applications, ranging from seals [1][2][3][4], boundary and mixed lubrication [5][6][7][8], adhesive tapes, MEMS and NEMS, and friction [9][10][11][12]. In the last years two main approaches have been developed to study the contact mechanics of an elastic body when it is brought into contact with a rough surface: (i) multiasperity contact theories [13][14][15][16][17] where the contact between the surfaces is modelled as an ensemble of randomly distributed Hertzian contacts between the asperities, and (ii) Persson's theory of contact mechanics [9,18,19], where the probability 2 G. Carbone, E. Pierro / distribution of the contact pressure is shown to be governed by a diffusive process.…”