0

Full Content is available to subscribers

Subscribe/Learn More  >

DGV’s Accuracy Dependence Upon Laser Beam Intensity Profile

[+] Author Affiliations
Gerald L. Morrison, Saikishan Suryanarayanan

Texas A&M University, College Station, TX

Paper No. FEDSM2009-78245, pp. 21-26; 6 pages
doi:10.1115/FEDSM2009-78245
From:
  • ASME 2009 Fluids Engineering Division Summer Meeting
  • Volume 2: Fora
  • Vail, Colorado, USA, August 2–6, 2009
  • Conference Sponsors: Fluids Engineering Division
  • ISBN: 978-0-7918-4373-4 | eISBN: 978-0-7918-3855-6
  • Copyright © 2009 by ASME

abstract

A Doppler Global Velocimeter (DGV) system was designed for use in high speed rotating equipment at the Turbomachinery Laboratory. Due to the rapidly varying periodic nature of flows inside turbines, compressors, and pumps, it is desirable to use a pulsed laser as the light source. An ND-YAG laser was selected for use based upon the 9 ns pulse duration and the ability for the laser to operate with a 15 MHz light bandwidth which is tunable to the absorption line filter used in the DGV system. However, when applied to the system it was discovered the DGV system did not work properly. The output of a line CCD array used to monitor the laser frequency was closely scrutinized. The light intensity across the laser beam was not Gaussian in nature but contained a very large amount of “noise”. Since the DGV system measures light intensity variations to infer Doppler shifts and hence velocity distributions, the rapidly spatially varying light intensity across the laser beam was suspected as the cause of the system’s inaccuracy. An analysis to quantify how the laser beam light intensity profile noise affects a DGV system accuracy is performed and possible remedies are suggested.

Copyright © 2009 by ASME
Topics: Laser beams

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In