Numerical Simulation and Experimental Analysis of Chaotic Mixing in Two-Fluid Flow

• Main Authors: Kuo-Wei Lin, 林國偉
• Other Authors: Jing-Tang Yang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/52825294320518113777

博士 === 國立清華大學 === 動力機械工程學系 === 95 === This work finishes two-fluid mixing via numerical simulation and experimental measuremet. Mixing indexes, mixing mechanism, mixer of a planar serpentine channel with alternating cross sections is designed, simulated, and verified. Mixing indexes for miscible fluids, immiscible fluids, and two-phase fluids are designated as the standard deviation of concentration, interface to volume ratio, and the sum of interval of particles. Fast flow or great ratio of cross sections increases the pressure gradient and the Dean number. In coordinate with a suitable inlet fluid distribution, fluid mixing can be promoted. Below Reynolds number 102, flow velocity does not perturbed by experiencing a repeated channel; but the trajectory does. At Reynolds number 0.87, for aspect ratio 2, the increased mixing degree is 32% as compared to the serpentine channel; for Reynolds number 13.9, it rises up to 47%. For fluids of different densities, to keep momentum balance, the heavy fluid trends to locate at the region of slow flow. At Reynolds number 16 and Dean number 12.27, a difference of 0.5% makes apparent separation. Overall, this work has great contribution on microscale two-fluid mixing in process of mixing indexes analysis, mechanism of fluid mixing, numerical simulation of fluid mixing, fabrication of fluidic mixer, and measurement of fluid mixing.