Investigation of Size Effects to the Mixing Performance on the X-shaped Micro-Channels

Due to the developing of micro-electro-mechanical-system, MEMS, the fabrication of the microminiaturization devices becomes obviously important. The advances in the basic understanding of fluid physics have opened an era of application of fluid dynamics systems using microchannels. The purpose of this study is to research the flow transport phenomenon by employing different kinds of micro-channel sizing in X-shaped micro-channels. As the working fluid, water is injected to microchannel at different mass flow rate. Over a wide range of flow condition, 1.06 < Re < 514, in X-shaped micro-channels, the mixture performances of numerical simulation, flow visualization, and temperature distribution remain the same. At the same mass flow rate as the Reynolds number below 112.53, the biggest channel size had the slowest flow velocity and got the best mixing performance; as the Reynolds number above 112.53, the smaller the channel sizing, the lower the pressure drops and the faster velocity becomes. The transition form early from laminar flow, the unsteady flow is an advantage for mixing in the limited mixing area, therefore 0.7 mm got the best mixing performance. It is clear that the size of the channel plays an important role in the X-shaped micro-channels.

[1]  S. Garimella,et al.  A COMPARATIVE ANALYSIS OF STUDIES ON HEAT TRANSFER AND FLUID FLOW IN MICROCHANNELS , 2001, Proceeding of Heat Transfer and Transport Phenomena in Microscale.

[2]  Man Wong,et al.  Phase change in microchannel heat sinks with integrated temperature sensors , 1999 .

[3]  R. Shah.  Laminar Flow Forced convection in ducts , 1978 .

[4]  R. L. Zhang,et al.  HEAT TRANSFER AND FRICTION IN SMALL DIAMETER CHANNELS , 1998 .

[5]  Dongqing Li,et al.  Flow characteristics of water in microtubes , 1999 .

[6]  Robin H. Liu,et al.  Passive mixing in a three-dimensional serpentine microchannel , 2000, Journal of Microelectromechanical Systems.

[7]  K. Wise,et al.  Pressure sensitivity in anisotropically etched thin-diaphragm pressure sensors , 1979, IEEE Transactions on Electron Devices.

[8]  R. Shah,et al.  Meso- and Micro-Scale Frontiers of Compact Heat Exchangers , 1999 .

[9]  Numerical investigation into thermal mixing efficiency in Y-shaped channel using Lattice Boltzmann method and field synergy principle , 2009 .

[10]  Kwang-Yong Kim,et al.  Evaluation of the mixing performance of three passive micromixers , 2009 .

[11]  M. Gad-el-Hak.  The Fluid Mechanics of Microdevices—The Freeman Scholar Lecture , 1999 .

[12]  Zhang Weifeng,et al.  Numerical Research on the Fiber Suspensions in a Turbulent T-shaped Branching Channel Flow , 2007 .

[13]  O. Tabata,et al.  Surface micromachined micro-diaphragm pressure sensors , 1991, TRANSDUCERS '91: 1991 International Conference on Solid-State Sensors and Actuators. Digest of Technical Papers.

[14]  Tim Ameel,et al.  Single phase forced convection heat transfer in microgeometries-a review , 1995 .

[15]  W. Little,et al.  Measurement of the heat transfer characteristics of gas flow in fine channel heat exchangers used for microminiature refrigerators , 1984 .

[16]  X. Peng,et al.  Experimental investigation on liquid forced-convection heat transfer through microchannels☆ , 1994 .

[17]  Muammer Koç,et al.  Fabrication of micro-channel arrays on thin metallic sheet using internal fluid pressure: Investigations on size effects and development of design guidelines , 2008 .

[18]  Gian Piero Celata,et al.  EXPERIMENTAL INVESTIGATION OF HYDRAULIC AND SINGLE-PHASE HEAT TRANSFER IN 0.130-MM CAPILLARY TUBE , 2002, Proceeding of Heat Transfer and Transport Phenomena in Microscale.

[19]  Xiao-gang Wang,et al.  Three-Dimensional Simulation for Effects of Bed Discordance on Flow Dynamics at Y-Shaped Open Channel Confluences , 2007 .