LASER DOPPLER VELOCIMETRY AND CONFINED FLOWS

Main Article Content

Jelena T. ILIĆ Slavica S. RISTIĆ Milesa Ž. SREĆKOVIĆ

Abstract

Finding the mode, in which two component laser Doppler velocimetry can be applied to flows confined in cylindrical tubes or vessels, was the aim of this study. We have identified principle issues that influence the propagation of laser beams in laser Doppler velocimetry system, applied to flow confined in cylindrical tube. Among them, the most important are influences of fluid and wall refractive indices, wall thickness and internal radius ratio and beam intersection angle. In analysis of the degrees of these influences, we have applied mathematical model, based on geometrical optics. The separation of measurement volumes, that measure different velocity components, has been recognized as the main drawback. To overcome this, we propose a lens with dual focal length – primary focal length for the measurement of one velocity component and secondary focal length for the measurement of the other velocity component. We present here the procedure for calculating the optimal value of secondary focal length, depending on experimental set-up parameters. The mathematical simulation of the application of the dual focal length lens, for chosen cases presented here, confirmed the accuracy of the proposed procedure.

Article Details

How to Cite
ILIĆ, Jelena T.; RISTIĆ, Slavica S.; SREĆKOVIĆ, Milesa Ž.. LASER DOPPLER VELOCIMETRY AND CONFINED FLOWS. Thermal Science, [S.l.], mar. 2017. ISSN 2334-7163. Available at: <http://thermal-science.tech/journal/index.php/thsci/article/view/2371>. Date accessed: 20 feb. 2018. doi: https://doi.org/10.2298/TSCI160720278I.
Section
Articles
Received 2017-03-10
Accepted 2017-03-14
Published 2017-03-14

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