TY - JOUR
T1 - Combustion in meso-scale vortex chambers
AU - Wu, Ming Hsun
AU - Wang, Yanxing
AU - Yang, Vigor
AU - Yetter, Richard A.
N1 - Funding Information:
This work was supported by the Air Force Office of Scientific Research under Contract AFOSR F49620-01-1-0376. The authors gratefully acknowledge the support from Dr. Mitat Birkan, contract monitor, of the program.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2007
Y1 - 2007
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
AN - SCOPUS:34548737827
VL - 31 II
SP - 3235
EP - 3242
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
SN - 1540-7489
T2 - 31st International Symposium on Combustion
Y2 - 5 August 2006 through 11 August 2006
ER -