Theoretical and Numerical studies of Viscous Air Damping in Laterally Oscillating Micro Comb Structures

• Main Authors: Chia-Fen Tsou, 鄒佳芬
• Other Authors: Ching-Shung Chen
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/11955024599651699443

碩士 === 淡江大學 === 航空太空工程學系 === 89 === This paper studies analytically as well as numerically viscous air damping in laterally oscillating micro comb structures. The influences of dimension and frequency on viscous damping are investigated. The Knudsen numbers in typical micro comb structures indicate part of the flow falling in the slip flow region. The slip effect is also studied. The analytical results demonstrate that the transient motion is damped out in less than one oscillating period of the model system. The analytical quality factors subject to slip and nonslip boundary conditions are both larger than experimental data. The numerical procedure solves the unsteady two-dimensional incompressible Navier-Stokes equations. The Marker-And-Cell (MAC) finite difference method and a Poisson equation solver are used to solve the equations. The numerical quality factors compare quite well with experimental data. The possible explanation for the discrepancy between analytical and numerical results are that analytical solutions assume the structure is infinite in the lateral direction, while numerical solutions treat the structure as finite, the edge and finite-size effects are included.