Interaction of steady jets with an array of permeable screens

Interaction of steady jets with an array of permeable screens Turbulent flows in porous media have important practical applications such as enhanced mixing of fuel and air, food drying, and cooling of electronics. However, experimental studies of turbulence in porous media are sparse due to the difficulties of measuring the complex flow environment. To this end, the interactions of steady jets with a porous medium formed from several parallel, transparent, permeable screens are studied using digital particle image velocimetry in a refractive indexed-matched environment. The permeable screens had porosities (open area ratios, ϕ) of 83.8, 69.0, 55.7, and 49.5 % and were held by a transparent frame that allowed the screen spacing to be changed. The steady jet results for Reynolds number (Re), which is defined based on the jet exit velocity and jet diameter, of 1000 showed laminar, predominantly steady flow that was segregated inside the porous medium, but for Re ≥ 2000, the flow was unsteady and turbulent with a mean velocity field that was relatively smooth inside the porous medium. As a result, more traditional jet features of self-similarity and increasing jet width were compared for the Re ≥ 2000 results. Decreasing the porosity was observed to increase the width of the jet significantly, especially for low porosity screens, and slowed the jet flow speed. Some of the typical features for axisymmetric jets were observed, even though the flow impinged on the permeable screens. In particular, self-similarity (or near self-similar behavior) was observed for the cross-sectional mean velocity profiles and for turbulence quantities for porosities larger than 55.7 % inside the porous medium. The effect of ϕ on turbulence quantities was significant for Re ≥ 2000. Although turbulence intensity increased on the downstream side of the first screen, the high dissipation forced drastic decrease of turbulence levels further downstream in the porous domain. Finally, the screens increased the removal of momentum from the jet as porosity decreased and screen spacing had a significant effect on the removal rate. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Experiments in Fluids Springer Journals

Interaction of steady jets with an array of permeable screens

Loading next page...
 
/lp/springer_journal/interaction-of-steady-jets-with-an-array-of-permeable-screens-EbWBK20Dm5
Publisher
Springer Berlin Heidelberg
Copyright
Copyright © 2015 by Springer-Verlag Berlin Heidelberg
Subject
Engineering; Engineering Fluid Dynamics; Fluid- and Aerodynamics; Engineering Thermodynamics, Heat and Mass Transfer
ISSN
0723-4864
eISSN
1432-1114
D.O.I.
10.1007/s00348-015-1925-7
Publisher site
See Article on Publisher Site

References

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

$49/month

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.

$588

$360/year

billed annually
Start Free Trial

14-day Free Trial