Please use this identifier to cite or link to this item:
Designs of Micro-mixer and Micro-fluidic Switch
Hsing, Tsai Shun
In this study, CFD (Computational Fluid Dynamics) was employed as a tool to design two microfluidoic devices, passive micromixer and flow switch. In the passive mixer design, complete three-dimensional fluid and species transport equations were solved to realize the mixing effectiveness of the designed mixers. In the flow switch, Volume of Fluid method was employed in carrying out in the flow stream direction prediction.
In the passive mixer, the mixer was designed to possess triangular wavy sidewalls The basic principle is to enhance the species mixing by improving the flow exchange in the diffusive direction due to change in flow passage. The amplitude and wave number was designed to relate to the channel depth. DI water was used as the working fluid. The inlet velocity was in the range of 0.0008 to 0.8m/sec. The species molecular diffusivity was in the range from to . Based on these flow and species parameters, it was found that the minimum wave amplitude and numbers to achieve complete mixing were 5H and 8 when H=70um. The outlet channel length required to achieve complete mixing (defined as mixing length) was 8mm. By reducing the depth to 35um and maintaining the amplitude at 5H, the same mixing length was obtained but with the wave number increased to 16. However, the required driving pressures increased dramatically.
In the design of microfluidic switch, we attempt to design a simple microfluidic system that can perform flow metering and switching at the same time. From the simulation, it was found that flow metering and switching can be achieved by suitable adjustment of flow rate of the sheath flow. The test fluid can be switched into one, two, or three branches with flow rates depending on the cross section area and averaged velocity of each branch.
|Appears in Collections:||機械工程學系所|
Show full item record
TAIR Related Article
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.