• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>International Conference on Microchannels and Minichannels >UNIQUE CHARACTERISTICS OF ADIABATIC GAS-LIQUID FLOWS IN MICROCHANNELS: DIAMETER AND SHAPE EFFECTS ON FLOW PATTERNS, VOID FRACTION AND PRESSURE DROP
【24h】

UNIQUE CHARACTERISTICS OF ADIABATIC GAS-LIQUID FLOWS IN MICROCHANNELS: DIAMETER AND SHAPE EFFECTS ON FLOW PATTERNS, VOID FRACTION AND PRESSURE DROP

机译：微通道中绝热气液流动的独特特性：对流动模式的直径和形状效应，空隙分数和压降

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Microfluidics is a rapidly developing area of research with great potential for a wide range of applications in many fields. One area of microfluidics is gas-liquid two-phase flow in microchannels, which is important for the development of microreactors, lab-on-a-chip systems, micro heat exchangers and micro-heat pipes, among others, that are highly relevant to industry. Recently, much interest has also been shown toward studying the two-phase flow in micro fuel cells. This keynote paper presents a state-of-the-art review of past and present research on adiabatic two-phase flow in minichannels and microchannels, which are considered to have channel diameters between 250 μm ― 6 mm, and less than 250 μm, respectively. From this review, certain differences between minichannels and microchannels are identified. These notable differences are also explained, based on some of our recent experiments on two-phase flow in microchannels. Our experiments have been performed using several microchannels to determine the effects of the microchannel diameter and shape on the adiabatic two-phase flow of nitrogen gas and de-ionized water. The effect of channel geometry was examined by characterizing the two-phase flow in a circular and square microchannel of similar hydraulic diameter. A video camera was used to capture images of the gas-liquid interfacial structure. From the video recordings, it became clear that the channel size strongly influences the two-phase flow patterns occurring in the circular microchannel. The flow pattern was predominantly intermittent, exhibiting alternating sequences of liquid and gas slugs. Only slug flow was observed in the microchannel for all flow conditions tested. There were no instances of bubbly flow, churn flow, slug-annular or annular flow, as reported for minichannels. Instead, four new sub-classes of slug flow were defined to better describe the interfacial structure in the time average sense: slug-ring flow, ring-slug flow, semi-annular flow and multiple flow. The time-averaged void fraction was estimated from the recorded images of the two-phase flow structure. It was found that as the channel diameter decreased, the void fraction data deviated more from those obtained for minichannels. A new void fraction correlation was developed for both the circular and square microchannels, which differs significantly from those developed for minichannels.
机译：Microfluidics是一种迅速发展的研究领域，具有许多领域各种应用的潜力。微流体的一个区域是微通道的气液两相流，这对于显微反应器，芯片芯片系统，微热交换器和微热管的开发是重要的，这与其高度相关行业。最近，还朝着研究微燃料电池中的两相流来显示了很多兴趣。该主题纸介绍了对过去的过去和目前研究的最先进的审查，并将其在微通道中的绝热两相流程，其被认为分别具有250μm-6mm，小于250μm的通道直径。从本次审查中，识别迷你沟槽和微通道之间的某些差异。基于我们最近的微通道中的两相流的一些实验，还解释了这些显着差异。我们的实验已经使用多个微通道进行，以确定微通道直径和形状对氮气和去离子水的绝热两相流的影响。通过表征相似液压直径的圆形和方形微通道中的两相流来检查通道几何的效果。使用摄像机捕获气液界面结构的图像。从视频录制中，声明频道大小强烈影响圆形微通道中发生的两相流动模式。流动模式主要是间歇性的，表现出液体和气体块的交替序列。在微通道中仅观察到SLUP流程，用于测试所有流动条件。如图所据道，由于较小的宣传纳，因此没有气泡流动，流失流动，脱块环或环形流动的情况。相反，定义了四个新的SLUG流量的子类别，以更好地描述时间平均感觉中的界面结构：块环流，环形块流，半环形流量和多个流动。从两相流结构的记录图像估计时平均空隙分数。发现，随着沟道直径减小，空隙率数据偏离更多地偏离了MiniCannels的那些。为圆形和方形微通道开发了一种新的空隙率相关性，这与为迷你宣传士开发的那些不同。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号