High-resolution imaging of dissipative structures in a turbulent jet flame with laser Rayleigh scattering

High-resolution imaging of dissipative structures in a turbulent jet flame with laser Rayleigh... High-resolution 2-D imaging of laser Rayleigh scattering is used to measure the detailed structure of the thermal dissipation field in a turbulent non-premixed CH4/H2/N2 jet flame. Measurements are performed in the near field (x/d = 5–20) of the flame where the primary combustion reactions interact with the turbulent flow. The contributions of both the axial and radial gradients to the mean thermal dissipation are determined from the 2-D dissipation measurements. The relative contributions of the two components vary significantly with radial position. The dissipation field exhibits thin layers of high dissipation. Noise suppression by adaptive smoothing enables accurate determination of the dissipation-layer widths from single-shot measurements. Probability density functions (PDF) of the dissipation-layer widths conditioned on temperature are approximately log-normal distributions. The conditional layer width PDFs are self-similar functions with the layer widths scaling with temperature to the 0.75 power. The high signal-to-noise ratio of the Rayleigh scattering images coupled with an interlacing technique for noise suppression enable fully resolved measurements of the mean power spectral density (PSD) of the temperature gradients. These spectra are used to determine the turbulence microscales by measuring a cutoff wavelength, λ C , at 2% of the peak PSD. The Batchelor scale is estimated from λ C , and the results are compared with estimates from scaling laws in non-reacting flows. At x/d = 20, the different approaches to determining the Batchelor scale are comparable on the jet centerline. However, the estimates from non-reacting flow scaling laws are significantly less accurate in off-centerline regions and at locations closer to the nozzle exit. Throughout the near field of the jet flame, the measured ratio of a characteristic dissipation-layer width to the local Batchelor scale is larger than values previously reported for the far field of non-reacting flows. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Experiments in Fluids Springer Journals

High-resolution imaging of dissipative structures in a turbulent jet flame with laser Rayleigh scattering

Loading next page...
Copyright © 2007 by Springer-Verlag
Engineering; Engineering Fluid Dynamics; Fluid- and Aerodynamics; Engineering Thermodynamics, Heat and Mass Transfer
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial