Virginia Tech
An experimental investigation of the effect of temporal equivalence ratio fluctuations on NO<sub>x</sub> emissions in premixed flames
Abstract
dc:description.abstractThe effect of temporal variations in equivalence ratio on the NO<sub>x</sub> emissions of a premixed methane-air flame was measured in a burner. The NO<sub>x</sub> emissions are compared among steady flames with spatially uniform equivalence ratio distributions, steady flames with spatially nonuniform equivalence ratio distributions, and unsteady flames with temporal equivalence ratio fluctuations. Time-varying equivalence ratio was measured optically, time-varying temperatures were measured with thermocouples, and mean NO<sub>x</sub> emissions were measured by probe sampling and a chemiluminescent analyzer. These measurements quantify the effect of temporal unsteadiness and spatial nonuniformity of equivalence ratio on NO<sub>x</sub> emissions. For lean flames, both spatial nonuniformities and temporal fluctuations in equivalence ratio contribute to an increase in NO<sub>x</sub> emissions with respect to steady uniform flames at the same mean flame temperatures. For lean flames, higher amplitude temperature fluctuations result in larger increases in NO<sub>x</sub> with respect to steady flames. The dissertation also describes the optical technique for nonintrusive temporal measurements of equivalence ratio fluctuations and techniques for thermocouple compensation at frequencies up to 10 Hz.
Degree
thesis:*- Name thesis:degree_name
- Ph. D.
- Level thesis:degree_level
- doctoral
- Discipline thesis:degree_discipline
- Mechanical Engineering
- Department dc:contributor.department
- Mechanical Engineering
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 1993
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Wirth, Douglas A.
- Chair dc:contributor.committeechair
-
- Mahan, Robert
- Committee members dc:contributor.committeemember
-
- Cox, David
- Davis, L. Berkley
- Roe, Larry A.
- Roby, Richard J.
- Vandsburger, Uri
Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
- Language dc:language.iso
- en
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-06062008-144729
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/37948