4. Conclusions

(1) The lubrication performance of the multi-layer materials is better than that of the single layer materials. Also, it can be significantly improved if considering the surface Darcy flow. Within a certain range, the effects of surface Darcy flow on the lubrication performance are more obviously with higher speed.

(2)The lower permeability surface is beneficial to improve the lubrication property of the multi-layer porous bearing when the total porosity is certain. There is a good agreement between the numerical analysis and the measurement. Therefore, when design the multi-layer oil bearing, the surface porosity should be reduced as far as possible if the oil content is guaranteed. This work is beneficial for the analysis of the tribological property and the structural design of multi-layer bearing.
