Research on Temperature/Velocity Measurement Technique Utilizing Laser-Doppler Velocimetory with Fluorescent Seed Particles

荧光种子粒子激光多普勒测速温度/速度测量技术研究

• 批准号: 07650242
• 负责人: SATOH Isao
• 金额: $ 1.34万
• 依托单位: TOKYO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650242/
• 关键词: Temperature; Velocity Measurement; Simultaneous Measurement; LDV; Fluorescent Seed Particles; Lifetime of Fluorescence; Monochromator; Phase Shift; Smoothing Effect; 強度変調; 固気二相流; 粒子温度

In order to examine the mechanism of heat transfer in heterogeneous heat transfer media, e.g.gas-solid two-phase flow, from microscopic view point, it is keenly required to develop the technique for simultaneous measurement of temperature and velocity of the media in local basis. In this research project, the concept of a temperature/velocity measurement technique utilizing Laser-Doppler Velocimetory (LDV) with fluorescent seed particles was proposed, and its feasibility was experimentally examined. To examine the feasibility of the technique, an optical setup of LDV was constructed by using an Ar^+ ion laser (visible light) or a He-Cd gas laser (UV light), and the fluorescent seed particles dispersed in the heat transfer medium enable us to measure the fluorescent light, from which the temperature of medium was evaluated, as well as the scattered light for the velocity measurement. Obtained results can be summarized as follows :1. In the simultaneous measurement for the temperature and velocity of the same seed particle, fluorescent light and scattered light can be effectively separated by using a monochromator. The measurement of fluorescent light through the monochromator would improve the accuracy of temperature measurement, since the lifetime of fluorescence depends upon the wavelength of the fluorescent light.2. The fluorescent particles developed for the fluorescent lamps and/or CRT display are suitable as the seed particles, since the particles emit relatively strong fluorescent light in visible wavelength range. However the decay of fluorescence of these particles after the excitation is quite slower than the rising, and thus the temperature dependence of fluorescent lifetime of these particles can be observed not as the phase shift but as the change of smoothing effect on the Doppler burst signal.

为了从微观角度研究非均质传热介质（如气固两相流）的传热机理，迫切需要发展局部同时测量介质温度和速度的技术。在本研究项目中，提出了利用激光多普勒测速（LDV）与荧光种子粒子的温度/速度测量技术的概念，并通过实验验证了其可行性。为了验证该技术的可行性，通过使用Ar^+离子激光器（可见光）或He-Cd气体激光器（紫外光）构建LDV的光学装置，并且分散在传热介质中的荧光种子颗粒使我们能够测量荧光，由此评估介质的温度，以及用于速度测量的散射光。所获得的结果可以概括如下：1.在同时测量同一种子粒子的温度和速度时，利用单色器可以有效地分离荧光和散射光。通过单色器测量荧光将提高温度测量的准确性，因为荧光的寿命取决于荧光的波长。2.为荧光灯和/或CRT显示器开发的荧光颗粒适合作为种子颗粒，因为这些颗粒在可见波长范围内发射相对强的荧光。然而，这些粒子的荧光在激发后的衰减比上升慢得多，因此这些粒子的荧光寿命的温度依赖性可以被观察到不是作为相移，而是作为对多普勒猝发信号的平滑效应的变化。