A novel laser Doppler anemometer (LDA) for high-accuracy turbulence measurements

Yaacob, Mohd Rusdy and Schlander, Rasmus Korslund and Buchhave, Preben and Velte, Clara Marika (2022) A novel laser Doppler anemometer (LDA) for high-accuracy turbulence measurements. Journal Of Advanced Research In Applied Sciences And Engineering Technology, 28 (2). pp. 256-274. ISSN 2462-1943

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Abstract

High accuracy and dynamic range have been some of the most prominent challenges when it comes to fine-scale turbulence measurements. The current commercial LDA processors, which perform the signal processing of Doppler bursts directly using hardware components, are essentially black boxes and in particular are renown for suffering from practical limitations that reduce the measurement reliability and accuracy. A transparently functioning novel LDA, utilizing advanced technologies and up-to-date hardware and software has therefore been developed to enhance the measurement quality and the dynamic range. In addition, the self-developed software comes with a highly flexible functionality for the signal processing and data interpretation. The LDA setup and the combined forward/side scattering optical alignment (to minimize the effective measuring volume) are described first, followed by a description of the signal processing aspects. The round turbulent jet has been used as the test bed since it presents a wide range of degree of difficulty for the LDA processor (accuracy, dynamic range etc.) across the different radial distances and downstream development. The data are diagnosed for dynamic range in residence and interarrival times, and compared to a typical hardware driven processor. The radial profiles of measured mean streamwise velocity and variance agree well with previous studies of the round jet. The spatial turbulent kinetic energy spectra in the fully developed region perfectly match the expected (and in this region well established) -5/3 power law even for the largest measured distances from the centerline (where shear and turbulence intensity are significant).

Item Type:	Article
Uncontrolled Keywords:	Turbulent round jet, Laser Doppler anemometer, Turbulence measurements
Divisions:	Faculty of Electrical Engineering
Depositing User:	mr eiisaa ahyead
Date Deposited:	13 Feb 2023 16:36
Last Modified:	23 Feb 2023 16:36
URI:	http://eprints.utem.edu.my/id/eprint/26302
Statistic Details:	View Download Statistic

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