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.

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.

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

Turbulent Jet Diffusion Flames in Environments Containing Some Premixed Fuel

1988 ◽  
Vol 110 (3) ◽  
pp. 146-150 ◽  
Author(s):  
M. G. Kibrya ◽  
G. A. Karim
Keyword(s):  
Diffusion Flame ◽  
Diffusion Flames ◽  
Turbulent Jet ◽  
Gaseous Fuels ◽  
Model Based ◽  
Jet Diffusion Flames ◽  
Experimental Values ◽  
Additional Fuel ◽  
Good Agreement

The blowout limit of a methane jet diffusion flame is extended by adding small concentrations of a fuel to the surrounding air. The improvement is predicted theoretically with a model based on the stoichiometric changes within the jet and in its vicinity due to the presence of this additional fuel. Good agreement was obtained between such a prediction and the corresponding experimental values for a range of gaseous fuels in the surrounding air.

Numerical Simulation of Jet Diffusion Flames With Radiative Heat Transfer Modeling

2005 ◽  
Author(s):  
Mario Baburic´ ◽  
Reinhard Tatschl ◽  
Neven Duic´
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Radiative Heat Transfer ◽  
Diffusion Flame ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
Flamelet Model ◽  
Jet Flame ◽  
Combustion Modeling ◽  
Jet Diffusion Flames

Beside appropriate turbulence and combustion modeling, the problem of an accurate prediction of turbulent diffusion flames usually requires accurate radiative heat transfer predictions as well. In this paper it is shown that the inclusion of radiation modeling into the overall numerical simulation is important if accurate temperature profiles are needed. Two different jet diffusion flame configurations are simulated in this work — a diluted hydrogen jet flame (80% H2 and 20% He by volume) [1–4], and a piloted methane jet diffusion flame (flame D) [5, 6]. The predictions are compared to experimental data. Radiation is modeled by a conservative discrete transfer radiation method (DTRM) [7, 8]. Turbulence is modeled by a classical k-ε and by a hybrid procedure, as proposed in [9]. Combustion modeling is based on the stationary laminar flamelet model (SLFM) [10], where the combustion/turbulence interaction is accomplished via the presumed β probability density function (β-PDF).

A new mathematical method for quantifying trajectory of buoyant line-source gaseous fuel jet diffusion flames in cross air flows

Fuel ◽  
2016 ◽  
Vol 177 ◽  
pp. 107-112 ◽  
Author(s):  
Xiaochun Zhang ◽  
Wenhao Xu ◽  
Longhua Hu ◽  
Xiaozhou Liu ◽  
XiaoLei Zhang ◽  
...  
Keyword(s):  
Mathematical Method ◽  
Line Source ◽  
Diffusion Flames ◽  
Gaseous Fuel ◽  
Jet Diffusion Flames ◽  
Fuel Jet ◽  
Air Flows

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.

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