PARAMETRIC STUDIES OF MICROCHANNEL CONJUGATE LIQUID FLOWS WITH ZETA POTENTIAL EFFECTS
PARAMETRIC STUDIES OF MICROCHANNEL CONJUGATE LIQUID FLOWS WITH ZETA POTENTIAL EFFECTS
复制标题
DOI：
10.1142/s0960313100000290
复制
发表时间：
2000-12
期刊：
影响因子：
--
通讯作者：
E. Ng;S. T. Poh
中科院分区：
文献类型：
--
作者：
E. Ng;S. T. Poh
本文提出了一种计算机模型，使用有限体积方案来研究微通道中的液体流动和传热，以流动势为驱动力。引入双电层（EDL）的概念来解释微尺度偏差。 EDL 等界面动电现象在微通道的各种传输过程中发挥着重要作用。传统的流体力学和传热理论无法解释在微通道中观察到的这些现象。 EDL 的存在降低了微通道内的液体速度，从而影响压力驱动微通道中的传热机制。在本文中，将体力形式的源项包含在控制动量方程中，用于微尺度计算以及通过通道壁的传热效应。进行的数值参数研究得出这样的结论：微通道中的流动和传热特性取决于体离子浓度、Zeta 电位和通道的纵横比，这是 EDL 效应的反映。当纵横比减小时，EDL 的存在更加显着。此外，摩擦系数随着 KCL 水溶液的离子浓度降低和系统 Zeta 电位增加而增加。然而，应该意识到，10-8 M 的离子浓度实际上不太可能。
This paper presents a computer model with the use of a finite-volume scheme on the liquid flow and heat transfer in microchannels, with streaming potential as the driving force. The concept of electric double layer (EDL) was introduced to explain the microscale deviation. Interfacial electrokinetic phenomena such as the EDL play important roles in various transport processes in microchannels. Conventional theories of fluid mechanics and heat transfer cannot explain these phenomena observed in microchannels. The presence of the EDL reduces the liquid velocity within the microchannel, which affects the heat transfer mechanism in the pressure-driven microchannels. In this paper, a source term in the form of the electrical body force was included in the governing momentum equations for microscale computation with the effects of the heat transfer through the channel wall. The numerical parametric studies performed allowed the conclusion that the flow and heat transfer characteristics in microchannels depend on the bulk ionic concentration, the Zeta potential and the aspect ratio of the channel, which is the reflection of the EDL effects. The existing of the EDL is more significant as aspect ratios decrease. Also, the friction coefficient increases as the ionic concentration of the aqueous KCL solution decreases and the Zeta potential of the system increases. However, one should be aware that the ionic concentration of 10-8 M is unlikely in reality.