82
Views
4
CrossRef citations to date
0
Altmetric
Original Articles

CO/NOx Emissions of Strongly Pulsed Jet Diffusion Flames

&
Pages 536-554 | Received 14 Dec 2007, Accepted 28 Oct 2008, Published online: 09 Jun 2010
 

Abstract

The CO and NOX emissions of strongly pulsed, turbulent diffusion flames were examined experimentally in a co-flow combustor. Video imaging was performed and time-averaged emissions were measured at the combustor exit and near the visible flame tip. Both the case of a fixed fuel injection velocity during the injection interval and a constant fuelling rate were studied for jet Reynolds numbers ranging from 5,000 to 15,000. For fixed injection velocity, maximum emission indices of CO occurred for compact, isolated flame puffs. CO decreased substantially with decreasing jet-off time as the flame puff interaction increased. The pulsed flames had lower NOX than the steady flames, particularly for the case of isolated flame structures. Similar trends in NO formation were seen for constant fueling rate. The CO emissions were, however, considerably different, largely due to a significant impact of the Reynolds number. Radial emissions profiles suggest an improved fuel/air mixing for shorter jet-off times and longer jet-on times. The correlation of CO/NO emissions with a global flame residence time is discussed.

This work was supported by the National Aeronautics and Space Administration under Cooperative Agreement NNC04AA37A. The help of Jennifer Tsai and Ying-Hao Liao for some of the data analysis is also appreciated.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.