Choi Dongwhi, Lee Donghyeon, Kim Dong Sung
Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, Gyeongbuk, 790-784, South Korea.
Sci Rep. 2015 Oct 14;5:15172. doi: 10.1038/srep15172.
In this study, we first suggest a simple approach to characterize configuration of gas-aqueous liquid two-phase flow based on discrete solid-liquid contact electrification, which is a newly defined concept as a sequential process of solid-liquid contact and successive detachment of the contact liquid from the solid surface. This approach exhibits several advantages such as simple operation, precise measurement, and cost-effectiveness. By using electric potential that is spontaneously generated by discrete solid-liquid contact electrification, the configurations of the gas-aqueous liquid two-phase flow such as size of a gas slug and flow rate are precisely characterized. According to the experimental and numerical analyses on parameters that affect electric potential, gas slugs have been verified to behave similarly to point electric charges when the measuring point of the electric potential is far enough from the gas slug. In addition, the configuration of the gas-aqueous liquid two-phase microfluidic system with multiple gas slugs is also characterized by using the presented approach. For a proof-of-concept demonstration of using the proposed approach in a self-triggered sensor, a gas slug detector with a counter system is developed to show its practicality and applicability.
在本研究中，我们首先提出一种基于离散固液接触起电来表征气-液两相流形态的简单方法，离散固液接触起电是一个新定义的概念，它是固液接触以及接触液体从固体表面相继脱离的连续过程。该方法具有操作简单、测量精确和成本效益高等优点。通过利用离散固液接触起电自发产生的电势，气-液两相流的形态（如气塞大小和流速）得以精确表征。根据对影响电势的参数进行的实验和数值分析，当电势测量点距离气塞足够远时，已证实气塞的行为类似于点电荷。此外，所提出的方法还用于表征具有多个气塞的气-液微流体系统的形态。为了对在自触发传感器中使用该方法进行概念验证演示，开发了一种带有计数系统的气塞探测器以展示其实用性和适用性。
