Dynamic permeability of highly compressible porous layers under squeeze at constant velocity and under impact

The ability of a highly compressible porous layer (HCPL), imbibed with a Newtonian liquid, to dissipate energy is underlined in recent papers related to ex-poro-hydrodynamic (XPHD) lubrication. The total absorption of energy of a squeeze/impact is due to the hydrodynamic forces generated within the HCPL. Mostly all XPHD processes take place in dynamic conditions, therefore it is essential to know if the permeability determined at constant thickness is adequate for such processes. For this reason, squeeze at constant velocity and impact tests were performed on HCPLs completely saturated with Newtonian liquids, thus the variation of dynamic permeability was determined.

Research Highlights
► Highly compressible porous layers (HCPL) are deformable porous materials.
► HCPLs saturated with liquid are used in ex-poro-hydrodynamic lubrication (XPHD).
► Two dynamic experiments were performed: squeeze at constant velocity and under impact.
► A method to determine the dynamic permeability of HCPL was introduced.
► The difference between static, quasi-static and dynamic permeability is shown.