Three Dimensional Simultaneous Measurements of Concentration and Velocity Field in a Serpentine Channel

• Main Authors: Chu-Hsiang Wu, 吳楚翔
• Other Authors: Jing-Tang Yang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/20580098608490759788

碩士 === 國立臺灣大學 === 機械工程學研究所 === 98 === The purpose of this thesis is to apply a newly invented simultaneously measuring technique to a planar serpentine microreactor, and to construct the whole flow field, including three-dimensional concentration and velocity field, inside the microreactor. The confocal microscopy and micro-PIV (micro particle image velocimetry) techniques are combined to obtain the concentration information and velocity data in-plane. By stacking up velocity data in different focal planes, the three-dimensional velocity vectors can be determined based on the continuity equation. Flow fields of low Reynolds number are fully constructed and verified with the numerical simulation. The three-dimensional velocity measurement outcome shows great consistency with the simulation results. Due to the accelerating and centrifugal effect of serpentine geometry, the out-of plane velocity component is observed in both the measurement and the simulation. Mixing index of Re = 0.04 and 0.1 are calculated through the concentration data obtained by particle counting method. However, a noticeable amount of difference is shown in the mixing index calculations comparing with numerical simulation. The results suggest that there are actually some unpredictable variables, such as particle aggregation, particle adhesion to walls, and clogging problems, in experimental tests. Mixing efficiency of microreactors may be excessively estimated if designers ignore these crucial factors. The application of a novel simultaneously measuring technique and the construction method of three-dimensional flow field inside a microreactor are demonstrated in this article. The combination of these techniques provides a useful and reliable tool to analyze flow conditions inside microreactors of biomedical use.