TY - JOUR

T1 - Electroosmotic flow driven by DC and AC electric fields in curved microchannels

AU - Chen, Jia Kun

AU - Luo, Win Jet

AU - Yang, Ruey Jen

N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2006/10/15

Y1 - 2006/10/15

N2 - The purpose of this study is to investigate electroosmotic flows driven by externally applied DC and AC electric fields in curved microchannels. For the DC electric driving field, the velocity distribution and secondary flow patterns are investigated in microchannels with various curvature ratios. We use the Dean number to describe the curvature effect of the flow field in DC electric field. The result implies that the effect of curvatures and the strength of the secondary flows become get stronger when the curvature ratio of C/A (where C is the radius of curvature of the microchannel and A is the half-height of rectangular curved tube.) is smaller. For the AC electric field, the velocity distribution and secondary flow patterns are investigated for driving frequencies in the range of 2.0kHz (Wo = 0.71) to 11 kHz (Wo = 1.66). The numerical results reveal that the velocity at the center of the microchannel becomes lower at higher frequencies of the AC electric field and the strength of the secondary flow decreases. When the applied frequency exceeds 3.0kHz (Wo = 0.87), vortices are no longer observed at the corners of the microchannel. Therefore, it can be concluded that the secondary flow induced at higher AC electric field frequencies has virtually no effect on the axial flow field in the microchannel.

AB - The purpose of this study is to investigate electroosmotic flows driven by externally applied DC and AC electric fields in curved microchannels. For the DC electric driving field, the velocity distribution and secondary flow patterns are investigated in microchannels with various curvature ratios. We use the Dean number to describe the curvature effect of the flow field in DC electric field. The result implies that the effect of curvatures and the strength of the secondary flows become get stronger when the curvature ratio of C/A (where C is the radius of curvature of the microchannel and A is the half-height of rectangular curved tube.) is smaller. For the AC electric field, the velocity distribution and secondary flow patterns are investigated for driving frequencies in the range of 2.0kHz (Wo = 0.71) to 11 kHz (Wo = 1.66). The numerical results reveal that the velocity at the center of the microchannel becomes lower at higher frequencies of the AC electric field and the strength of the secondary flow decreases. When the applied frequency exceeds 3.0kHz (Wo = 0.87), vortices are no longer observed at the corners of the microchannel. Therefore, it can be concluded that the secondary flow induced at higher AC electric field frequencies has virtually no effect on the axial flow field in the microchannel.

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U2 - 10.1143/JJAP.45.7983

DO - 10.1143/JJAP.45.7983

M3 - Article

AN - SCOPUS:34547865040

VL - 45

SP - 7983

EP - 7990

JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes

JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes

SN - 0021-4922

IS - 10 A

ER -