Liquid Phase Velocity Profile Measurement in Two-Phase Flow by Micro Tracer Method

微量示踪法测量两相流中的液相速度分布

• 批准号: 04650190
• 负责人: KAJI Masuo
• 金额: $ 1.02万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650190/
• 关键词: Gas-Liquid Two-Phse Flow; Velocity Profile; Hydrogen Bubble Method; Tracer Method; Image Processing; Particle Image Velocimetry; Time Line Method; マイクロトレーサ; 液膜; 可視化

Liquid phase velocity profile of gas-liquid two-phase flow is an important information to understand the flow mechanism of two-phase flow. Micro tracer mathods were applied to measure the liquid velocity profile in two-phase flows and validity of these methodes were discussed.The time line method by using hydrogen bubbles was applied to a air-water two-phase horizontal flow. This method is valid for the separated flow when both the gas and liquid velocities are relative low. When the gas velocity is high, the liquid velocity becomes high and hydrogen bubbles cannot be clearly distinguished. However, Probability is considerd to be high if the particle image velocimetry technique is applied to hydrogen bubble traces.For the vertical upward two-phase plow in a round tube, fine particles were contained in the liquid phase and traced by making use of CCD camera. This method is a particle image velocimetry techique. To determine precisely the measurement position in a round tube, an optical system was designed and geomerical relations were drived. Results obtained for the single phase water flow are satisfacrory. For the gas-liquid two-phase flow, accurate data cannot be obtained. This is attributable to the fact that the number of tracer is very small at measurement points close to the wall and that the accuracy of the present optical system generates considerable error.

气液两相流液相速度分布是了解两相流流动机理的重要信息。本文应用微示踪法测量了气液两相流中的液相速度分布，并对这些方法的有效性进行了讨论，将氢气泡时间线法应用于水平气液两相流中。该方法适用于气液两相流速较低时的分离流。当气体速度高时，液体速度变高并且氢气泡不能被清楚地区分。然而，粒子图像测速技术应用于氢气泡追踪的可能性很高。对于圆管中垂直向上的两相犁，利用CCD相机对液相中的细颗粒进行追踪。该方法是一种粒子图像测速技术。为了精确确定圆管内的测量位置，设计了光学系统，推导了几何关系式。对单相水流动的计算结果是令人满意的。对于气液两相流，无法获得准确的数据。这是由于在靠近壁的测量点处示踪剂的数量非常小，并且本光学系统的精度产生相当大的误差。