Abstract
Vortex flows were utilized as a means to stabilize gaseous flames in meso-/micro-scale non-premixed combustors for use in small-scale power and propulsion systems. Scaling studies were performed with a series of combustors ranging in size from ∼10.6 to 124 mm3 (i.e., combustor diameters of 2.4-6.4 mm). Three-dimensional modeling of reacting flows was also conducted to explore flame stabilization mechanism and flow evolution in the chamber. Combustor performance was evaluated by analyzing the stability limit and chemical efficiency. Both hydrogen and hydrocarbons (methane and propane) have been studied with the chemical energy varying from 25 to 174 W. For the largest combustion volume, hydrogen and hydrocarbons burned efficiently in air. However, for smaller volumes, oxygen enrichment in air was required to stabilize hydrocarbon flames. Flame stabilization was achieved by a large, relatively quiescent, hot core flow that was formed by the flow recirculation at the head- and tail-ends of the combustor. The stability limits for hydrogen/air mixtures, in terms of the overall equivalence ratio, were found to be ~0.25 on the lean-side and in the range of 3-6 on the rich-side. The corresponding chemical efficiency exceeded 97%. For propane/air combustion, the stability limits ranged from ∼0.25 to 2 for the 124 mm3 combustor. Methane was the most difficult fuel to stabilize the flame and required oxygen-enriched air containing 40% O2 and 60% N2 by volume to operate in the 10.6 mm3 combustor with a chemical efficiency of more than 85%.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3235-3242 |
| Number of pages | 8 |
| Journal | Proceedings of the Combustion Institute |
| Volume | 31 II |
| DOIs | |
| State | Published - Sep 24 2007 |
| Event | 31st International Symposium on Combustion - Heidelberg, Germany Duration: Aug 5 2006 → Aug 11 2006 |
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All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Mechanical Engineering
- Physical and Theoretical Chemistry
Cite this
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Combustion in meso-scale vortex chambers. / Wu, Ming Hsun; Wang, Yanxing; Yang, Vigor; Yetter, Richard A.
In: Proceedings of the Combustion Institute, Vol. 31 II, 24.09.2007, p. 3235-3242.Research output: Contribution to journal › Conference article
TY - JOUR
T1 - Combustion in meso-scale vortex chambers
AU - Wu, Ming Hsun
AU - Wang, Yanxing
AU - Yang, Vigor
AU - Yetter, Richard A.
PY - 2007/9/24
Y1 - 2007/9/24
N2 - Vortex flows were utilized as a means to stabilize gaseous flames in meso-/micro-scale non-premixed combustors for use in small-scale power and propulsion systems. Scaling studies were performed with a series of combustors ranging in size from ∼10.6 to 124 mm3 (i.e., combustor diameters of 2.4-6.4 mm). Three-dimensional modeling of reacting flows was also conducted to explore flame stabilization mechanism and flow evolution in the chamber. Combustor performance was evaluated by analyzing the stability limit and chemical efficiency. Both hydrogen and hydrocarbons (methane and propane) have been studied with the chemical energy varying from 25 to 174 W. For the largest combustion volume, hydrogen and hydrocarbons burned efficiently in air. However, for smaller volumes, oxygen enrichment in air was required to stabilize hydrocarbon flames. Flame stabilization was achieved by a large, relatively quiescent, hot core flow that was formed by the flow recirculation at the head- and tail-ends of the combustor. The stability limits for hydrogen/air mixtures, in terms of the overall equivalence ratio, were found to be ~0.25 on the lean-side and in the range of 3-6 on the rich-side. The corresponding chemical efficiency exceeded 97%. For propane/air combustion, the stability limits ranged from ∼0.25 to 2 for the 124 mm3 combustor. Methane was the most difficult fuel to stabilize the flame and required oxygen-enriched air containing 40% O2 and 60% N2 by volume to operate in the 10.6 mm3 combustor with a chemical efficiency of more than 85%.
AB - Vortex flows were utilized as a means to stabilize gaseous flames in meso-/micro-scale non-premixed combustors for use in small-scale power and propulsion systems. Scaling studies were performed with a series of combustors ranging in size from ∼10.6 to 124 mm3 (i.e., combustor diameters of 2.4-6.4 mm). Three-dimensional modeling of reacting flows was also conducted to explore flame stabilization mechanism and flow evolution in the chamber. Combustor performance was evaluated by analyzing the stability limit and chemical efficiency. Both hydrogen and hydrocarbons (methane and propane) have been studied with the chemical energy varying from 25 to 174 W. For the largest combustion volume, hydrogen and hydrocarbons burned efficiently in air. However, for smaller volumes, oxygen enrichment in air was required to stabilize hydrocarbon flames. Flame stabilization was achieved by a large, relatively quiescent, hot core flow that was formed by the flow recirculation at the head- and tail-ends of the combustor. The stability limits for hydrogen/air mixtures, in terms of the overall equivalence ratio, were found to be ~0.25 on the lean-side and in the range of 3-6 on the rich-side. The corresponding chemical efficiency exceeded 97%. For propane/air combustion, the stability limits ranged from ∼0.25 to 2 for the 124 mm3 combustor. Methane was the most difficult fuel to stabilize the flame and required oxygen-enriched air containing 40% O2 and 60% N2 by volume to operate in the 10.6 mm3 combustor with a chemical efficiency of more than 85%.
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U2 - 10.1016/j.proci.2006.08.114
DO - 10.1016/j.proci.2006.08.114
M3 - Conference article
VL - 31 II
SP - 3235
EP - 3242
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
SN - 1540-7489
ER -