A database for Couette flow rate considering the effects of non-symmetric molecular interactions

A complete database for Couette flow rate (Q_c(D,α₁,α₂), 0.1 ≤ α₁, α₂ ≤ 1.0, 0.01 ≤ D ≤ 100, where D=inverse Knudsen number) for ultra-thin gas film lubrication problems is advanced. When the accommodation coefficients (AC) of the two lubricating surfaces are different (α₁≠α₂), the Couette flow rate in the modified molecular gas film lubrication (MMGL) equation should be corrected. The linearized Boltzmann equation (under small Mach number conditions) is solved numerically for the case of non-symmetric molecular interactions (α₁ ≠ α₂). The Couette flow rate is then calculated, and the database is constructed. The present database can be easily implemented in the MMGL equation. In addition, the present database extends the previously published results for 0.1 ≤ α₁, α₂ ≤ 0.7. The database for low ACs is valuable in the analysis and applications of MEMS devices (bushings of electrostatic micro motors, micro bearings, magnetic head/disk interfaces, etc.), and their future development.