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Pulsed, high-power LED illumination for tomographic particle image velocimetry

Buchmann, Nicolas A. and Willert, Christian and Soria, Julio (2012) Pulsed, high-power LED illumination for tomographic particle image velocimetry. Experiments in Fluids, 53 (5), pp. 1545-1560. Springer Verlag. DOI: 10.1007/s00348-012-1374-5. ISSN 0723-4864.

Full text not available from this repository.

Official URL: http://link.springer.com/article/10.1007/s00348-012-1374-5

Abstract

This paper investigate the use of high-power light emitting diode (LED) illumination for Tomographic Particle Image Velocimetry (PIV) as an alternative to traditional laser-based illumination. Modern solid-state LED devices can provide averaged radiant power in excess of 10W and by operating the LED with short high current pulses theoretical pulse energies up to several tens of mJ can be achieved. In the present work, a custom build drive circuit is used to drive a Luminus PT-120 high power LED at pulsed currents of up to 150A and 1ms duration. Volumetric illumination is achieved by directly projecting the LED into the flow to produce a measurement volume of ~3-4 times the size of the LED die. The feasibility of the volumetric LED illumination is assessed by performing tomographic PIV of homogenous, grid-generated turbulence. Two types of LEDs are investigated and the results are compared with measurements of the same flow using pulsed Nd:YAG laser illumination and DNS data of homogeneous isotropic turbulence. The quality of the results is similar for both investigated LEDs with no significant difference between the LED and Nd:YAG illumination. Compared with the DNS some differences are observed in the power spectra and the probability distributions of the fluctuating velocity and velocity gradients. These differences are attributed to the limited spatial resolution of the experiments and noise introduced during the tomographic reconstruction (i.e. ghost particles). The uncertainty in the velocity measurements associated with the LED illumination is estimated to approximately 0.2-0.3 pixel for both LEDs, which compares favourably with similar tomographic PIV measurements of turbulent flows. In conclusion, the proposed high-power, pulsed LED volume illumination provides accurate and reliable tomographic PIV measurements in water and presents a promising technique for flow diagnostics and velocimetry.

Document Type:Article
Title:Pulsed, high-power LED illumination for tomographic particle image velocimetry
Authors:
AuthorsInstitution or Email of Authors
Buchmann, Nicolas A.Monash University
Willert, Christianchris.willert@dlr.de
Soria, JulioMonash University
Date:September 2012
Journal or Publication Title:Experiments in Fluids
Refereed publication:Yes
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:53
DOI:10.1007/s00348-012-1374-5
Page Range:pp. 1545-1560
Publisher:Springer Verlag
ISSN:0723-4864
Status:Published
Keywords:tomographic PIV, grid turbulence, pulsed light source, light emitting diode, flow field measurement
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:Propulsion Systems
DLR - Research area:Aeronautics
DLR - Program:L ER - Engine Research
DLR - Research theme (Project):L - Virtual Engine and Validation Methods
Location: Köln-Porz
Institutes and Institutions:Institute of Propulsion Technology > Engine Measurement Systems
Deposited By: Dr.phil. Christian Willert
Deposited On:16 Nov 2012 11:42
Last Modified:07 Feb 2013 20:12

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