Characterization of soaked soft porous materials under cyclic compression for eX-Poro-HydroDynamic lubrication

eX-Poro-HydroDynamic (XPHD) lubrication is an innovative method in which soaked soft porous materials are used to store and provide lubricant to moving surfaces. Storing the fluid in the pores of the porous media eliminates the need for an external source of lubricant, thus making this approach environmentally friendly and enabling the use of lubricants such as water or other environmentally friendly lubricants. This study aims to carry out experimental and numerical characterizations of the mechanism of dynamic re-imbibition of porous materials. An experimental device is developed to cyclically compress an open-pore foam soaked in water at different frequencies. The experimental results show a direct link between the variation in the normal force, the appearance of air inside the imbibed foam, and the frequency of stress. These parameters influence the ability of the foam to re-soak in the decompression phase, and hence control the maximum normal load that can be generated in the contact. A numerical model based on the Darcy model is also developed, which takes into account the phenomenon of film rupture. The use of a numerical model is made possible by the preceding experimental determination of the water permeability of the foam. Initial comparisons with experimental results show good similarity. • Experimental characterization of the mechanism of dynamic re-imbibition of porous materials. • Numerical characterization of the mechanism of dynamic re-imbibition of porous materials. • Normal forces generated in the contact increase linearly with the solicitation frequency. • Permeability of the porous material have a strong influence on the performance of the system. • The developed model can be used for future modeling and optimization of XPHD thrust bearings.