Influence of a wavy boundary on turbulence.

Influence of a wavy boundary on turbulence. A previous paper from this laboratory presented measurements of turbulence that were made for water flowing over a wavy wall. The system was a 50 mm×600 mm rectangular channel for which the top wall was flat and the bottom wall was a train of sinusoidal waves with a wave length of 5 mm and a wave height of 0.50 mm. The Reynolds number, defined with the bulk velocity and the half-height of the channel, was 46,000. These conditions were such that a sand covered surface would be fully rough and characterized with a dimensionless sand roughness of k s +=104. The present paper presents measurements with Reynolds numbers of 11,000 and 3,200 for which the surface corresponds to the intermediate regime (k s +=22.4) and the hydraulically smooth regime (k s +=6.89). The measurements in the outer flow for k s +=22.4 differ from what is observed for k s +=104 in that the quadrant analysis of the Reynolds stress and the skewness coefficients for u i and v i are the same as found for flow over a flat boundary. Measurements of mean velocities, wall drag and turbulent intensities for k s +=6.89 are consistent with defining this surface as hydraulically smooth. Surprisingly the quadrant analysis of the Reynolds stress and measurements of the skewness factor for normal velocity fluctuations for k s +=6.89 are different from what is found for a flat surface. The contributions of quadrants 2 and 4 and their ratio are larger than what is found for a flat surface. Measurements for all three surfaces show smaller relative contributions for large wavenumber fluctuations. However, this is much more pronounced for k s +=6.89 and k s +=22.4. Experiments in Fluids Springer Journals

Influence of a wavy boundary on turbulence.

Loading next page...
Copyright © 2003 by Springer-Verlag
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