Effect of viscoelasticity on the flow pattern and the volumetric flow rate in electroosmotic flows through a microchannel
Effect of viscoelasticity on the flow pattern and the volumetric flow rate in electroosmotic flows through a microchannel
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DOI：
10.1039/b800185e
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发表时间：
2008-01-01
期刊：
影响因子：
6.1
通讯作者：
Lee, W. M.
中科院分区：
文献类型：
--
作者：
Park, H. M.;Lee, W. M.
许多基于芯片实验室的微系统处理诸如血液和DNA溶液的生物流体。这些流体是粘弹性的，并显示出非凡的流动行为，不存在于牛顿流体。采用合适的本构方程，可以用各种数值方法合理地模拟和预测这些奇异的流动行为。在本文中，我们研究粘弹性电渗流通过一个矩形直微通道有和没有压力梯度。结果表明，在相同的外电场和压力梯度下，粘弹性流体的体积流率与牛顿流体的体积流率有很大的不同。此外，当压力梯度施加在微通道上时，在粘弹性流体中出现明显的二次流，这对于通过直微通道的牛顿层流是不可能的。延迟或增强的体积流率和二次流对溶质在微通道中的分散有重要影响。
Many lab-on-a-chip based microsystems process biofluids such as blood and DNA solutions. These fluids are viscoelastic and show extraordinary flow behaviors, not existing in Newtonian fluids. Adopting appropriate constitutive equations these exotic flow behaviors can be modeled and predicted reasonably using various numerical methods. In the present paper, we investigate viscoelastic electroosmotic flows through a rectangular straight microchannel with and without pressure gradient. It is shown that the volumetric flow rates of viscoelastic fluids are significantly different from those of Newtonian fluids under the same external electric field and pressure gradient. Moreover, when pressure gradient is imposed on the microchannel there appear appreciable secondary flows in the viscoelastic fluids, which is never possible for Newtonian laminar flows through straight microchannels. The retarded or enhanced volumetric flow rates and secondary flows affect dispersion of solutes in the microchannel nontrivially.