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Nanosecond Structured Laser Illumination Planar Imaging for Single-Shot Imaging of Dense Sprays

Kristensson, Elias LU ; Berrocal, Edouard LU ; Richter, Mattias LU and Aldén, Marcus LU (2010) In Atomization and Sprays 20(4). p.337-343
Abstract
Recently, a novel laser imaging technique, structured laser illumination planar imaging (SLIPI), has demonstrated great potential for suppressing multiply scattered light in spray imaging. SLIP! uses a laser sheet whose intensity is modulated in the spatial domain. Directly scattered photons keep this structural information; whereas, photons that experienced several scattering events lose this information. Using a spatially modulated light source thus enables directly scattered photons to be distinguished from the multiple-scattering contribution. To homogeneously illuminate the spray, three images are required, where the intensity modulation is successively shifted vertically one third of a period. By adequately post processing these... (More)
Recently, a novel laser imaging technique, structured laser illumination planar imaging (SLIPI), has demonstrated great potential for suppressing multiply scattered light in spray imaging. SLIP! uses a laser sheet whose intensity is modulated in the spatial domain. Directly scattered photons keep this structural information; whereas, photons that experienced several scattering events lose this information. Using a spatially modulated light source thus enables directly scattered photons to be distinguished from the multiple-scattering contribution. To homogeneously illuminate the spray, three images are required, where the intensity modulation is successively shifted vertically one third of a period. By adequately post processing these images, the multiple-scattering contribution is diminished. However, the time interval within which these images are recorded must be short enough to freeze the flow motion, making single-shot SLIPI of highly atomizing sprays particularly challenging. In this article, a nanosecond SLIPI system capable of freezing flow motions up to similar to 600 m/s is presented. The instrument was tested on a hollow-cone water spray, running at an injection pressure of up to 50 bars, and high-resolution single-shot images, in which multiple-scattering effects were efficiently suppressed, were obtained. Such images provide detailed information of complex dynamic flow behavior occurring in the dense spray region, e.g., primary and secondary breakups. In addition, it is demonstrated how the liquid sheet length can be estimated by extracting the rms from such single-shot SLIPI images. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
single-shot imaging, multiple scattering suppression, planar structured illumination, flow diagnostics
in
Atomization and Sprays
volume
20
issue
4
pages
337 - 343
publisher
Begell House
external identifiers
  • wos:000278842300005
  • scopus:77953013458
ISSN
1936-2684
DOI
10.1615/AtomizSpr.v20.i4
language
English
LU publication?
yes
id
28fb9544-1668-4965-b92c-6d1c83b32f08 (old id 1630529)
date added to LUP
2010-07-21 15:51:27
date last changed
2018-05-29 12:06:39
@article{28fb9544-1668-4965-b92c-6d1c83b32f08,
  abstract     = {Recently, a novel laser imaging technique, structured laser illumination planar imaging (SLIPI), has demonstrated great potential for suppressing multiply scattered light in spray imaging. SLIP! uses a laser sheet whose intensity is modulated in the spatial domain. Directly scattered photons keep this structural information; whereas, photons that experienced several scattering events lose this information. Using a spatially modulated light source thus enables directly scattered photons to be distinguished from the multiple-scattering contribution. To homogeneously illuminate the spray, three images are required, where the intensity modulation is successively shifted vertically one third of a period. By adequately post processing these images, the multiple-scattering contribution is diminished. However, the time interval within which these images are recorded must be short enough to freeze the flow motion, making single-shot SLIPI of highly atomizing sprays particularly challenging. In this article, a nanosecond SLIPI system capable of freezing flow motions up to similar to 600 m/s is presented. The instrument was tested on a hollow-cone water spray, running at an injection pressure of up to 50 bars, and high-resolution single-shot images, in which multiple-scattering effects were efficiently suppressed, were obtained. Such images provide detailed information of complex dynamic flow behavior occurring in the dense spray region, e.g., primary and secondary breakups. In addition, it is demonstrated how the liquid sheet length can be estimated by extracting the rms from such single-shot SLIPI images.},
  author       = {Kristensson, Elias and Berrocal, Edouard and Richter, Mattias and Aldén, Marcus},
  issn         = {1936-2684},
  keyword      = {single-shot imaging,multiple scattering suppression,planar structured illumination,flow diagnostics},
  language     = {eng},
  number       = {4},
  pages        = {337--343},
  publisher    = {Begell House},
  series       = {Atomization and Sprays},
  title        = {Nanosecond Structured Laser Illumination Planar Imaging for Single-Shot Imaging of Dense Sprays},
  url          = {http://dx.doi.org/10.1615/AtomizSpr.v20.i4},
  volume       = {20},
  year         = {2010},
}