Qualification of oil-based tracer particles for heated Ludwieg tubes

Qualification of oil-based tracer particles for heated Ludwieg tubes The generation, insertion, pressurization and use of oil-based tracer particles is qualified for the application in heated flow facilities, typically hypersonic facilities such as Ludwieg tubes. The operative challenges are to ensure a sub-critical amount of seeding material in the heated part, to qualify the methods that are used to generate the seeding, pressurize it to storage tube pressure, as well as to test specific oil types. The mass of the seeding material is held below the lower explosion limit such that operation is safe. The basis for the tracers is qualified in off-situ particle size measurements. In the main part different methods and operational procedures are tested with respect to their ability to generate a suitable amount of seeding in the test section. For the best method the relaxation time of the tracers is qualified by the oblique shock wave test. The results show that the use of a special temperature resistant lubricant oil “Plantfluid” is feasible under the conditions of a Mach-6 Ludwieg tube with heated storage tube. The method gives high-quality tracers with high seeding densities. Although the experimental results of the oblique shock wave test differ from theoretical predictions of relaxation time, still the relaxation time of 3.2 μs under the more dense tunnel conditions with 18 bar storage tube pressure is low enough to allow the use of the seeding for meaningful particle image velocimetry studies. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Experiments in Fluids Springer Journals

Qualification of oil-based tracer particles for heated Ludwieg tubes

Loading next page...
Springer Berlin Heidelberg
Copyright © 2014 by Springer-Verlag Berlin Heidelberg
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