scholarly journals Flame structure and ignition limit of partially premixed cool flames in a counterflow burner

2017 ◽  
Vol 36 (1) ◽  
pp. 1513-1522 ◽  
Author(s):  
Christopher B. Reuter ◽  
Sang Hee Won ◽  
Yiguang Ju
Keyword(s):  
Flame Structure ◽  
Ignition Limit ◽  
Cool Flames ◽  
Partially Premixed

Flame structure interactions and state relationships in an unsteady partially premixed flame

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 1190-1199
Author(s):  
Suresh K. Aggarwal ◽  
Ishwar K. Puri
Keyword(s):  
Flame Structure ◽  
Premixed Flame ◽  
Partially Premixed ◽  
Partially Premixed Flame

H2/CO/air premixed and partially premixed flame structure at different pressures based on reaction limit analysis

2018 ◽  
Vol 63 (19) ◽  
pp. 1260-1266 ◽  
Author(s):  
Zaigang Liu ◽  
Wenjun Kong ◽  
Jean-Louis Consalvi ◽  
Wenhu Han
Keyword(s):  
Limit Analysis ◽  
Flame Structure ◽  
Premixed Flame ◽  
Partially Premixed ◽  
Partially Premixed Flame

The Structure of Two-Stage Counterflow n-Heptane-Air Flames

2000 ◽  
Author(s):  
S. K. Aggarwal ◽  
H. S. Xue
Keyword(s):  
Strain Rate ◽  
Reaction Zone ◽  
Equivalence Ratio ◽  
Flame Structure ◽  
Premixed Combustion ◽  
Premixed Flame ◽  
Partially Premixed Combustion ◽  
Reaction Zones ◽  
Partially Premixed ◽  
Partially Premixed Flame

Partially premixed flames are formed by mixing air (in less than stoichiometric amounts) into the fuel stream prior to the reaction zone, where additional air is available for complete combustion. Such flames can occur in both laboratory and practical combustion systems. In advanced gas turbine combustor designs, such as a lean direct injection (LDI) combustor, partially premixed combustion represents an impotent mode of burning. Spray combustion often involves partially premixed combustion due to the locally fuel vapor-rich regions. In the present study, the detailed structure of n-heptane/air partially premixed flame in a counterflow configuration is investigated. The flame is computed by employing the Oppdif code and a detailed reaction mechanism consisting of 275 elementary reactions and 41 species. The partially premixed flame structure is characterized by two-stage burning or two distinct but synergistically coupled reaction zones, a rich premixed zone on the fuel side and a ‘nonpremixed zone on the air side. The fuel is completely consumed in the premixed zone with ethylene and acetylene being the major intermediate species. The reactions involving the consumption of these species are found to be the key rate-limiting reactions that characterize interactions between the two reaction zones, and determine the overall fuel consumption rate. The flame response to the variations in equivalence ratio and strain rate is examined. Increasing equivalence ratio and/or strain rate to a critical value leads to merging of the two reaction zones. The equivalence ratio variation affects the rich premixed reaction zone, while the variation in strain rate predominantly affects the nonpremixed reaction zone. The flame structure is also characterized in terms of a modified mixture fraction (conserved scalar), and laminar flamelet profiles are provided.

Real-Time Prediction of Incipient Lean Blowout in a Partially Premixed, Liquid-Fueled Gas Turbine Combustor

2007 ◽  
Author(s):  
Tongxun Yi ◽  
Ephraim J. Gutmark
Keyword(s):  
Real Time ◽  
Gas Turbine ◽  
Flame Structure ◽  
Rayleigh Distribution ◽  
Operating Conditions ◽  
Statistical Characteristics ◽  
Lean Blowout ◽  
Time Prediction ◽  
Two Indices ◽  
Partially Premixed

The present paper addresses real-time prediction of incipient lean blowout (LBO) in partially premixed, liquid-fueled gas turbine combustors. Near-LBO combustion is characterized by the “intensified” low-frequency combustion oscillations, typically below 30 Hz. Two indices, namely the normalized chemiluminescence RMS and the normalized cumulative duration of LBO precursor events, are recommended for LBO prediction. Both indices are associated with the statistical characteristics of the flame structure, which changes from the normal distribution to the Rayleigh distribution at the approach of LBO. Both indices change little within a large range of equivalence ratios and start to shoot up only when LBO is approached. To use the two indices for LBO prediction, one needs to perform a detailed a priori LBO mapping under simulated engine operating conditions. However, the mapping can be done without running the engines very close to LBO.

An Experimental Study on CO Emission and Flame Structure in a Partially Premixed Broil Burner with Bumped Radiation Plate

2019 ◽  
Vol 24 (1) ◽  
pp. 25-31
Author(s):  
Geunhyung Lee ◽  
Geunhyung Lee ◽  
Youngsoo Kim
Keyword(s):  
Experimental Study ◽  
Flame Structure ◽  
Partially Premixed ◽  
Co Emission

Flame Structure Interactions and State Relationships in an Unsteady Partially Premixed Flame

AIAA Journal ◽  
10.2514/2.530 ◽  
1998 ◽  
Vol 36 (7) ◽  
pp. 1190-1199 ◽  
Author(s):  
Suresh K. Aggarwal ◽  
Ishwar K. Puri
Keyword(s):  
Flame Structure ◽  
Premixed Flame ◽  
Partially Premixed ◽  
Partially Premixed Flame

A numerical investigation of the flame structure of an unsteady inverse partially premixed flame

1997 ◽  
Vol 111 (4) ◽  
pp. 296-311 ◽  
Author(s):  
Zhuang Shu ◽  
Suresh K. Aggarwal ◽  
Viswanath R. Katta ◽  
Ishwar K. Puri
Keyword(s):  
Numerical Investigation ◽  
Flame Structure ◽  
Premixed Flame ◽  
Partially Premixed ◽  
Partially Premixed Flame
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