Subatmospheric Extinction of Opposed-Jet Diffusion Flames of Jet Fuel and Its Surrogates

AIAA Journal ◽  
2010 ◽  
Vol 48 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Srinivasan Dattarajan ◽  
Okjoo Park ◽  
Elizabeth M. Fisher ◽  
Frederick C. Gouldin ◽  
Joseph W. Bozzelli
Keyword(s):  
Diffusion Flames ◽  
Jet Fuel ◽  
Jet Diffusion Flames ◽  
Opposed Jet

Effect of Diluent on the Blowout Limits of Jet Diffusion Flames

2001 ◽  
Author(s):  
N. Papanikolaou ◽  
I. Wierzba ◽  
V. W. Liu
Keyword(s):  
Carbon Dioxide ◽  
Experimental Investigation ◽  
Flow Field ◽  
Diffusion Flames ◽  
Jet Fuel ◽  
Field Structure ◽  
Jet Diffusion Flames ◽  
Air Stream ◽  
Lifted Flames

Abstract The paper will describe the results of an experimental investigation on the effect of diluents premixed with either the jet or co-flowing air stream on the blowout limits and flow field structure of jet diffusion flames. Experiments were conducted for a range of co-flowing air stream velocities with methane as the primary jet fuel, and nitrogen and carbon dioxide as diluents in the jet fuel; carbon dioxide was also used in the co-flowing air stream. The addition of a diluent to the surrounding air stream had a much stronger effect on the blowout limits than the addition of the diluent to the jet fuel. The effect of partially premixing air with the jet fuel on the blowout limits was also investigated. The addition of air (to up to 30%) to the methane jet significantly reduced the blowout limits of lifted flames, but it had little effect on the blowout limits of attached flames, which was rather unexpected.

Extinction of Opposed Jet Diffusion Flames of Scramjet Fuel Components at Subatmospheric Pressures

2008 ◽  
Author(s):  
Srinivasan Dattarajan ◽  
Christopher Montgomery ◽  
Frederick Gouldin ◽  
Elizabeth Fisher ◽  
Joseph Bozzelli
Keyword(s):  
Diffusion Flames ◽  
Jet Diffusion Flames ◽  
Fuel Components ◽  
Opposed Jet

The Increase in the Maximum Heat-Release Rate and Apparent Flame Strength of Opposed-Jet Diffusion Flames Under Impressed Electric Fields

1966 ◽  
Vol 88 (2) ◽  
pp. 157-164
Author(s):  
Bernard J. Rezy ◽  
Robert J. Heinsohn
Keyword(s):  
Electric Field ◽  
Heat Release ◽  
Electric Fields ◽  
Heat Release Rate ◽  
Release Rate ◽  
Field Experiments ◽  
Diffusion Flames ◽  
Maximum Heat ◽  
Jet Diffusion Flames ◽  
Opposed Jet

This paper is concerned with a study of the behavior of opposed-jet diffusion flames subjected to electrostatic fields. A theory for an idealized diffusion flame is presented which predicts an increase in the maximum volumetric heat-release rate when a flame is subjected to an electric field. Experiments reveal that the maximum mass flow into the flame increases with the application of an electric field.

Lift-Off Stability of n-Heptane Jet Diffusion Flames in Homogeneous Environments of Fuel and Air

1997 ◽  
Vol 119 (1) ◽  
pp. 45-48
Author(s):  
P. Samuel ◽  
G. A. Karim
Keyword(s):  
Liquid Fuel ◽  
Diffusion Flames ◽  
Jet Fuel ◽  
Small Concentration ◽  
Stream Velocity ◽  
Jet Flame ◽  
Jet Diffusion Flames ◽  
Discharge Velocity ◽  
Lift Off ◽  
Made In

The lift-off of jet diffusion flames of a liquid fuel in coflowing streams of air was established experimentally for a range of jet discharge and stream velocities. The improvement in the lift-off stability of the flame due to the presence of a small concentration of an auxiliary gaseous fuel in the surrounding air was established. Liquid n-heptane was the jet fuel while methane, ethylene, propane, and hydrogen were employed individually in small concentrations as the auxiliary fuels. It is shown that the lift-off distance and the corresponding ignition delay of the jet flame can be correlated for all the observations made in terms of derived dimensionless grouping of the main parameters varied, which included the jet discharge velocity, the surrounding stream velocity, and the concentration of the fuel added to the surroundings of the flame.

Examination of the Flame Blowout Characteristics of a Jet Diffusion Flames Burner in Co- and Cross-Flowing Air

2002 ◽  
Author(s):  
M. G. Kibrya ◽  
G. A. Karim
Keyword(s):  
Diffusion Flame ◽  
Diffusion Flames ◽  
Cross Flow ◽  
Jet Fuel ◽  
Flow Conditions ◽  
Uniform Velocity ◽  
Jet Diffusion Flames ◽  
Surrounding Atmosphere ◽  
Fuel Jet ◽  
Air Streams

The blowout limit of a jet diffusion flame was shown experimentally to improve significantly through the introduction of an auxiliary fuel in the surrounding air. A small experimental burner was devised so that the auxiliary fuel could be introduced and controlled independently of the main jet fuel, through a number of small pilot jets uniformly distributed around the main central fuel jet. This burner arrangement eliminated the likelihood of a flame flashing back into the surrounding atmosphere and some fuel escaping combustion. The burner was tested with methane as the fuel both for the main jet and the auxiliary side jets. Tests were made for both co-flow and cross-flow air streams of uniform velocity. It is shown that the arrangement adopted for auxiliary fuel introduction produced improvements in the flame blowout limits of the burner under both types of surrounding flow conditions. For the conditions considered, the blowout limits were of higher values in cross flow than for the corresponding co-flowing air streams.

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