Wang Haoli, Wang Yuan, Liu Jiang
(School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China)
Abstract: By choosing relativity roughness as the small parameter, perturbation
equations of laminar flow in micro-channel between two parallel plates were set up. The
perturbation equations were analyzed by the method of Fourier analysis and solved
numerically. The computing results show that the main factors affecting the flow pattern
are relative roughness and spatial wave number of wall rough curve. If the wave number
keeps constant and the relative roughness increases, the peak of the disturbed
non-dimensional stream function increases and the disturbed area in flow field is
invariable. If the relative roughness keeps constant and the spatial wave number
decreases, both the peak of disturbed stream function and disturbed area in flow field
increase simultaneously. Because of the existence of rough elements, obvious vortex
structures occur in the flow field near the wall. The vortex structures make viscous
dissipation augment and lead to the friction loss flowing in micro-channels larger than
that in macro-channels under the same conditions.
Keywords: perturbation analysis; micro-channel; rough element; flow pattern
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