Flow and liquid turbulence structure in developing two phase flow systems

开发两相流系统中的流动和液体湍流结构

• 批准号: 184014-2009
• 负责人: Ching, Chan
• 金额: $ 2.19万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=423011
• 关键词: Flow; liquid; turbulence; structure; developing

Gas-liquid two-phase flows are important in a number of engineering applications. For example, the safety analysis codes for the nuclear energy industry require closure relations for the vapor-liquid interfacial transfer terms, while accurate two phase pressure drop models are necessary to design the piping systems in the oil and gas industry. In these and other applications, the two phase flow can occur in complex piping geometries such as sudden area changes, orifices, bends and valves under a variety of flow conditions. Thus, it is important to understand the effect of different piping components on the two phase flow, especially in the developing regions downstream of these components, to develop reliable mechanistic models. The overall objective of this proposal is to investigate the flow and liquid turbulence structure of developing two-phase flows. In particular, the developing flow downstream of piping components and in the entrance regions will be investigated. The flow and turbulence structure of the two phase flows will be investigated using an existing 1.5-inch diameter horizontal air-water flow loop and a 8-inch vertical air-water flow loop. The local void distribution will be measured using capacitance and optical probes, while the liquid velocity and turbulence will be measured using hot film anemometry. A four-point optical probe will be used to determine the change in the bubble shape and size due to bubble coalescence/break-up. A high speed Particle Image Velocimetry (PIV) system will be adapted to measure the liquid turbulence field around the bubbles. There are few studies, especially of the flow and turbulence structure in the developing region of two-phase flows. However, this region is important in many multiphase systems and plays a determining role in many engineering applications. The measurements that will be performed here will be unique and provide physical insight into this complex phenomena and provide input to develop mechanistic models that can be incorporated into different engineering applications.

气液两相流在许多工程应用中是重要的。例如，核能工业的安全分析规范需要汽液界面传递项的闭合关系，而精确的两相压降模型对于设计石油和天然气工业中的管道系统是必要的。在这些和其他应用中，两相流可以发生在复杂的管道几何形状中，例如在各种流动条件下突然的面积变化、孔口、弯管和阀门。因此，重要的是要了解不同的管道组件对两相流的影响，特别是在这些组件下游的发展区域，以开发可靠的机理模型。本提案的总体目标是研究发展中的两相流的流动和液体湍流结构。特别是，将研究管道部件下游和入口区域的发展流。将使用现有的1.5英寸直径的水平空气-水流动回路和8英寸垂直空气-水流动回路来研究两相流的流动和湍流结构。局部空隙分布将使用电容和光学探针测量，而液体速度和湍流将使用热膜风速计测量。 将使用四点光学探针确定气泡聚结/破裂导致的气泡形状和尺寸变化。采用高速粒子图像测速（PIV）系统测量气泡周围的湍流场。两相流发展区的流动和湍流结构研究较少。 然而，这个区域在许多多相系统中是重要的，并且在许多工程应用中起着决定性的作用。将在这里进行的测量将是独特的，并提供对这种复杂现象的物理见解，并为开发可纳入不同工程应用的机械模型提供输入。