Elastic Turbulence of Aqueous Polymer Solution in Multi-Stream Micro-Channel Flow
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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Micromachines 2019, 10(2), 110; https://doi.org/10.3390/mi10020110
Received: 21 December 2018
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Revised: 31 January 2019
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Accepted: 3 February 2019
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Published: 7 February 2019
(This article belongs to the Special Issue Nanoparticles on Microfluidic Platforms)
Viscous liquid flow in micro-channels is typically laminar because of the low Reynolds number constraint. However, by introducing elasticity into the fluids, the flow behavior could change drastically to become turbulent; this elasticity can be realized by dissolving small quantities of polymer molecules into an aqueous solvent. Our recent investigation has directly visualized the extension and relaxation of these polymer molecules in an aqueous solution. This elastic-driven phenomenon is known as ‘elastic turbulence’. Hitherto, existing studies on elastic flow instability are mostly limited to single-stream flows, and a comprehensive statistical analysis of a multi-stream elastic turbulent micro-channel flow is needed to provide additional physical understanding. Here, we investigate the flow field characteristics of elastic turbulence in a 3-stream contraction-expansion micro-channel flow. By applying statistical analyses and flow visualization tools, we show that the flow field bares many similarities to that of inertia-driven turbulence. More interestingly, we observed regions with two different types of power-law dependence in the velocity power spectra at high frequencies. This is a typical characteristic of two-dimensional turbulence and has hitherto not been reported for elastic turbulent micro-channel flows.
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Keywords:
elastic turbulence; microfluidics; polymer solution; multi-stream micro-channel flow; contraction-expansion flow
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MDPI and ACS Style
Tai, J.; Lam, Y.C. Elastic Turbulence of Aqueous Polymer Solution in Multi-Stream Micro-Channel Flow. Micromachines 2019, 10, 110. https://doi.org/10.3390/mi10020110
AMA Style
Tai J, Lam YC. Elastic Turbulence of Aqueous Polymer Solution in Multi-Stream Micro-Channel Flow. Micromachines. 2019; 10(2):110. https://doi.org/10.3390/mi10020110
Chicago/Turabian StyleTai, Jiayan, and Yee C. Lam. 2019. "Elastic Turbulence of Aqueous Polymer Solution in Multi-Stream Micro-Channel Flow" Micromachines 10, no. 2: 110. https://doi.org/10.3390/mi10020110
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