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Korean Journal of Chemical Engineering, Vol.36, No.6, 837-842, 2019
Vortex generation by viscoelastic sheath flow in flow-focusing microchannel
Microfluidics-based technologies have attracted much attention since the fluid flow can be controlled precisely and only small sample volumes are required. Viscoelastic non-Newtonian fluids such as polymer solution and biofluids are frequently used in microfluidic analyses, and it is essential to understand the small-scale flow dynamics of such viscoelastic fluids. In this work, we report on vortex generation at the junction region of a flow-focusing microchannel, where a central flow stream of a Newtonian fluid meets two sheath flows of a non-Newtonian poly (ethylene oxide) aqueous solution. We elucidated the vortex-generation mechanism by the backward-flow component induced by the first normal stress difference in the viscoelastic sheath fluid. We systematically investigated the effects of polymer concentration, total flow rate, and total to central-stream flow-rate ratio, on the vortex generation. In addition, we demonstrated that this phenomenon can be engineered to enhance the mixing in the flow-focusing microchannel. We expect this work to be helpful for the understanding of viscoelastic flow dynamics in microscale flows and also for the development of microfluidic mixers.
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[Cited By]
- Park YM, Hong SO, Lee PC, Kim JM, Korea-Australia Rheology Journal, 31(4), 189, 2019
- Behdani B, Monjezi S, Zhang J, Wang C, Park JT, Korean Journal of Chemical Engineering, 37(12), 2117, 2020
- Qi C, Sun L, Wang Y, Wang C, Chen G, Korean Journal of Chemical Engineering, 38(8), 1592, 2021
- Shiriny A, Bayareh M, Nadooshan AA, Korean Journal of Chemical Engineering, 38(8), 1686, 2021
- Jung YY, Shim TS, Kim JM, Korean Journal of Chemical Engineering, 39(9), 2318, 2022
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