The performance of grooved air bearings in microsystems is analysed and discussed. The modified molecular gas lubrication (MMGL) equation is utilized as the governing equation for the gas film to include the effect of gas rarefaction. The gas rarefaction is significantly affected by two important parameters (Knudsen numbers (Kn) and accommodation coefficients (ACs)). The Poiseuille and Couette flowrate correctors (QP and QC) are introduced in the MMGL equation to extend the lubrication theory (compressible Reynolds equation) for arbitrary Kn and tangential momentum accommodation coefficients or ACs. At a specific operating condition, the transient MMGL equation is linearized by small variations in film thickness and pressure. The linearized MMGL equation is then solved by finite-element method to obtain the dynamic pressure distributions. Therefore, the dynamic coefficients (stiffness and damping coefficients) are obtained by integrating the dynamic pressure over the bearing surfaces.
|Number of pages||14|
|Journal||Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology|
|Publication status||Published - 2009 Sep 1|
All Science Journal Classification (ASJC) codes
- Mechanical Engineering
- Surfaces and Interfaces
- Surfaces, Coatings and Films