Micro-flow measurement with a laser diode micro-particle image velocimetry

In this paper, silicon-based micro-channels filled with deionized water and micro-beads were measured of their flow fields by using a self-improved micro-particle image velocimetry (MPIV). The designed channels were ranging from 100 to 300 mum in width and 60 Rm in depth, and the velocity was thousands of micrometers per second with Reynolds number <0.1. Commercial software CFD-ACE+ was used to simulate the flows. The simulation results showed great agreement with the measured results, implying that Navier-Stokes' equations still effectively governs the micro-scope flows in this scale. Two flow parameters-axial momentum number (K-a) and asymmetry number (K-a)-were discussed and were effectively evaluated the flow conditions with low Reynolds number. Preliminary result shows that short entrance length was found sufficient for fully developed flow in straight micro-channel. In addition, the flows in sharply expanded channels and serpentine channels are discussed. (C) 2004 Elsevier B.V. All rights reserved.