In order to examine the electroviscous effect of polar fluids on the friction factor for the laminar flow in microchannels
the numerical investigations were conducted
and the results were compared with the experimental data available in literature. Deionized water and tap water with different ion concentration and electrical conductivity were used as the working fluid. The finite volume method was adopted to discretize the governing equations. The effects of electrical potential
fluid ion concentration
electrical conductivity and the channel dimensions on the electrical double-layer profile
electroviscous effect and the friction coefficient were explored in detail. The numerical simulation results indicate that whether the electroviscous effect should be considered is determined by the ratio of channel hydraulic diameter to the Debye thickness. Smaller ratio leads to greater electroviscous effect. According to the experimental conditions
the electroviscous effect can be neglected completely at the ratio of 15. If the ratio decreases to 10
the electroviscous effect should be considered.
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references
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