Full Content is available to subscribers

Subscribe/Learn More  >

Evaluation of Directional Flame Thermometer for Real-Time Inversion of Heat Flux

[+] Author Affiliations
Philip Kokel, Craig Weinschenk, O. A. Ezekoye

University of Texas at Austin, Austin, TX

Paper No. IHTC14-22917, pp. 83-92; 10 pages
  • 2010 14th International Heat Transfer Conference
  • 2010 14th International Heat Transfer Conference, Volume 4
  • Washington, DC, USA, August 8–13, 2010
  • Conference Sponsors: Heat Transfer Division
  • ISBN: 978-0-7918-4939-2 | eISBN: 978-0-7918-3879-2
  • Copyright © 2010 by ASME


The Directional Flame Thermometer (DFT) is often used to measure heat flux during room fire testing. In literature and practice, heat transfer solutions for the DFT have been post processed. It is important to develop real-time capability for calculating heat flux based on measured temperatures as such capability will allow control of fire testing furnaces. In this study, we show that if a user will accept moderate errors in the heat flux, then a simple forward solution methodology allows heat flux measurements to be made in real-time. Essentially, the “inverse” problem is sufficiently well-conditioned to allow for a simple solution. Both a simple spreadsheet type solution and a finite difference code were used to generate the heat flux. The code was verified in both forward and inverse senses. The calculations were verified through a convergence study of both the forward and inverse solutions in spatial discretization (dx) and temporal discretization (dt). The inverse solution showed expected convergence behavior in both spatial and temporal discretization. In all cases, the solution for the front plate produced a maximum error of around 5%, which decreased as the DFT reached a steady state temperature. The forward and inverse models were validated through experimental testing using a radiant heater panel. The inverse model’s calculations were compared to measurements from a Schmidt-Boelter gage. The front plate heat flux measurements of the DFT matched reasonably well with the Schmidt-Boelter gage (2–6% difference) during the majority of the testing. The heat flux was then used to drive a forward simulation, and the forward model’s calculations were compared to actual temperature data acquired by the tests, producing a difference no greater than 4%. The DFT was also placed into a room fire to evaluate its effectiveness in this environment. The DFT was placed near a sand burner and in a panel fire test. The DFT produced reasonable heat flux values, but had more noise than results from those in front of the radiant heater panel (standard deviation of 1500 W/m2 compared to 400–600 W/m2 ).

Copyright © 2010 by ASME



Interactive Graphics


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

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