Influence of initial permeability on seepage behavior of the lubricant stored in hydrogel surface

This paper studied the unsteady seepage characteristics of lubricant stored in hydrogel under different initial permeability. Results show that the distribution of the permeability is determined by the deformation of hydrogel. The normal velocity and normal pressure gradient on the hydrogel surface have diffusion, fluctuation and stabilization processes. The normal pressure gradient is the internal cause that drives the change of the velocity. With the increase of the initial permeability, the seepage velocity increases significantly. Higher initial permeability leads to a higher exudation rate of hydrogel at the initial stage of loading, but the exudation is unsustainable. Considering the instantaneous seepage rate of the lubricant and the long-term lubrication, it is necessary to reasonably design the initial permeability.

Automated summary

This paper investigates the unsteady seepage characteristics of lubricant stored in hydrogel under different initial permeability. The study finds that the distribution of permeability depends on the deformation of hydrogel. The normal velocity and pressure gradient on the hydrogel surface exhibit diffusion, fluctuation, and stabilization processes. The change in velocity is driven by the internal cause of the normal pressure gradient. As the initial permeability increases, the seepage velocity significantly increases. A higher initial permeability leads to a higher exudation rate of hydrogel initially, but it is unsustainable. Therefore, it is necessary to design the initial permeability reasonably considering the instantaneous seepage rate and long-term lubrication.