Laser-induced plasma image velocimetry
File(s)
Author(s)
Shi, Zhengjie
Hardalupas, Ioannis
Taylor, AMKP
Type
Journal Article
Abstract
A novel velocimetry method is proposed for point velocity measurement, which is based on tracking a laser-induced plasma in a flow. The plasma’s behaviour is first analysed spatially, temporally and spectrally in quiescent air. The dependence of this technique on the delay time between subsequent plasma images and the processing methods are described. It is found that, for optimized operation of the technique in a turbulent air jet (exit diameter 10.0 mm from a 480 mm long pipe; with an averaged velocity of 50 m/s at the jet exit resulting in Reynolds number of 34,000) with 100 µs time delay between plasma images, the systematic and random components of the velocity uncertainty are − 0.51 m/s and ± 3.6 m/s along the laser beam direction, and 1.25 m/s and ± 0.86 m/s along other directions perpendicular to the laser beam. These uncertainties are mainly caused by the asymmetric laser energy deposition during the formation of plasma, and the associated spatial resolution (in this realisation of the instrument) of 5 mm. The mean velocity measurements in the turbulent air jet flow are consistent with the reported flow behaviour in the literature for mean velocity: the turbulent intensity of axial velocity fluctuations is comparable to those in the literature but difference arises due to the limited spatial resolution. This velocimetry method is an alternative to traditional tracer-based velocimetry methods, because it does not require ‘seeding’ of particles or other substances in the flow. It also has the ability to measure local gas mixture composition, using laser-induced breakdown spectroscopy approach, simultaneously with flow velocity, but this aspect is not explored in the current study.
Date Issued
2019-01-01
Date Acceptance
2018-11-12
Citation
Experiments in Fluids, 2019, 60
ISSN
0723-4864
Publisher
Springer Verlag
Journal / Book Title
Experiments in Fluids
Volume
60
Copyright Statement
© The Author(s) 2018.
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Sponsor
Engineering & Physical Science Research Council (E
Engineering & Physical Science Research Council (EPSRC)
Grant Number
J13878
EP/M015300/1
Subjects
Science & Technology
Technology
Engineering, Mechanical
Mechanics
Engineering
INDUCED BREAKDOWN SPECTROSCOPY
MOLECULAR TAGGING VELOCIMETRY
MAGNETIC-RESONANCE VELOCIMETRY
VELOCITY-MEASUREMENTS
SPARK-IGNITION
NUMERICAL-SIMULATION
DOPPLER VELOCIMETRY
TURBULENT
FLOW
PIV
0913 Mechanical Engineering
0915 Interdisciplinary Engineering
0901 Aerospace Engineering
Fluids & Plasmas
Publication Status
Published
Article Number
ARTN 5
Date Publish Online
2018-11-27