Expanding the applications of holographic interferometry to the quantitative visualization of oscillatory thermofluid processes using temperature as tracer
Expanding the applications of holographic interferometry to the quantitative visualization of oscillatory thermofluid processes using temperature as tracer
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DOI：
10.1007/s003480050193
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发表时间：
1998-05-01
影响因子：
2.4
通讯作者：
Wetzel, M
中科院分区：
文献类型：
--
作者：
Herman, C;Kang, E;Wetzel, M
在本文中，我们讨论了一种新的应用全息干涉术的同时定量可视化的高速，振荡流场和温度场在复杂的流动几何形状。我们考虑的情况下，（i）自持振荡流与主流施加在槽和沟通的渠道，以及（ii）振荡热流体过程中的零平均速度的热声制冷机模型。通过实时全息干涉测量结合高速摄影技术获得的非稳态温度分布的例子说明了本文所介绍的方法的可能性。我们的研究表明，温度分布准确地反映了某些类型的复杂的，不稳定的流的流动结构，从而允许，除了测量的温度分布和传热，也测量的振荡幅度，频率，波长以及传播速度的行波通过应用数字图像处理技术。在沟槽和通信通道中，可以通过使用全息干涉术的无限边缘场对准来可视化Tollmien-Schlichting波通过等温线的结构。在热声制冷机模型中，由声驻波产生的小幅度温度振荡被可视化和测量。本文讨论了用于分析这些流场的图像处理和数据处理程序。通过应用本文介绍的技术获得的实验数据与理论和数值模拟的结果显示出良好的一致性，我们的研究表明，使用温度作为示踪剂在某些类型的复杂，非定常流动的研究提供了许多优势。
In this paper we discuss a novel application of holographic interferometry in the simultaneous quantitative visualization of high-speed, oscillatory flow and temperature fields in complex flow geometries. We consider cases of (i) self-sustained oscillatory flows with main flow imposed in grooved and communicating channels as well as (ii) oscillating thermofluid processes with zero mean velocity in a thermoacoustic refrigerator model. Examples showing unsteady temperature distributions obtained by real-time holographic interferometry combined with high-speed cinematography illustrate the possibilities of the approach introduced in the paper. Our study shows that temperature distributions accurately mirror flow structures in certain types of complex, unsteady flows, thus allowing, apart from the measurement of temperature profiles and heat transfer, also the measurement of oscillatory amplitudes, frequencies, wavelengths as well as the speed of propagation of traveling waves by applying digital image processing techniques. In the grooved and communicating channels it is possible to visualize the structure of the Tollmien-Schlichting waves through isotherms by using the infinite fringe field alignment of holographic interferometry. In the thermoacoustic refrigerator model, small amplitude temperature oscillations generated by the acoustic standing wave are visualized and measured. Image processing as well as data reduction procedures used in the analysis of these flow fields are discussed in the paper. Experimental data obtained by applying the techniques introduced in the paper show good agreement with theory and results of numerical simulations, Our study suggests that using temperature as tracer offers numerous advantages in the study of certain types of complex, unsteady flows.