Structure of the Stabilizing Region of a Laminar Jet Diffusion Flame

1988 ◽  
Vol 110 (1) ◽  
pp. 182-189 ◽  
Author(s):  
F. Takahashi ◽  
M. Mizomoto ◽  
S. Ikai
Keyword(s):  
Diffusion Flame ◽  
Diffusion Flames ◽  
Back Diffusion ◽  
Velocity Data ◽  
Base Region ◽  
Flame Zone ◽  
Low Velocity ◽  
Laminar Jet ◽  
Major Species ◽  
Dark Space

Velocity, temperature, and composition of major species were measured in the base region of a two-dimensional, laminar methane jet diffusion flame in unconfined still air under a low-velocity jetting condition. The velocity data showed acceleration near the flame zone caused primarily by thermal expansion and buoyancy. The heat flux vectors showed substantial heat flow from the flame base to both downstream and the burner wall. The premixed zone was formed in the dark space by convective penetration of oxygen and back-diffusion of methane. The molar flux vectors of methane and oxygen at the base pointed to the opposite directions, typical of diffusion flames.

A PIV investigation of weakly buoyant laminar jet diffusion flames

2000 ◽  
Author(s):  
Mark Wernet ◽  
Paul Greenberg ◽  
Peter Sunderland ◽  
William Yanis
Keyword(s):  
Diffusion Flames ◽  
Laminar Jet ◽  
Jet Diffusion Flames

The prediction of laminar jet diffusion flame sizes: Part II. Experimental verification

1977 ◽  
Vol 29 ◽  
pp. 227-234 ◽  
Author(s):  
F.G. Roper ◽  
C. Smith ◽  
A.C. Cunningham
Keyword(s):  
Experimental Verification ◽  
Diffusion Flame ◽  
Laminar Jet

scholarly journals Investigation of Nonbuoyant Laminar Jet Diffusion Flames: A Paradigm for Soot Processes in Turbulent Flames

2004 ◽  
Author(s):  
Gerard Faeth ◽  
C. Aalburg ◽  
F. Diez ◽  
P. Sunderland ◽  
D. Urban ◽  
...  
Keyword(s):  
Diffusion Flames ◽  
Turbulent Flames ◽  
Laminar Jet ◽  
Jet Diffusion Flames

scholarly journals Soot formation in hydrocarbon/air laminar jet diffusion flames

1996 ◽  
Vol 27 (1) ◽  
pp. 87
Author(s):  
P.B. Sunderland ◽  
G.M. Faeth
Keyword(s):  
Diffusion Flames ◽  
Soot Formation ◽  
Laminar Jet ◽  
Jet Diffusion Flames

scholarly journals Soot nucleation and growth in weakly-buoyant laminar jet diffusion flames

1994 ◽  
Author(s):  
U. Koylu ◽  
P. Sunderland ◽  
S. Mortazavi ◽  
G. Faeth
Keyword(s):  
Diffusion Flames ◽  
Nucleation And Growth ◽  
Laminar Jet ◽  
Jet Diffusion Flames

On Blow-Out and Lift-Off of Laminar Jet Spray Diffusion Flames

2016 ◽  
Vol 188 (11-12) ◽  
pp. 1760-1776 ◽  
Author(s):  
Noam Weinberg ◽  
J. Barry Greenberg
Keyword(s):  
Diffusion Flames ◽  
Laminar Jet ◽  
Lift Off

scholarly journals Not gone with the wind: Planet occurrence is independent of stellar galactocentric velocity

2019 ◽  
Vol 489 (2) ◽  
pp. 2505-2510 ◽  
Author(s):  
Moiya A S McTier ◽  
David M Kipping
Keyword(s):  
Solar Neighbourhood ◽  
P Value ◽  
Selection Function ◽  
Strong Correlations ◽  
Velocity Data ◽  
Low Velocity ◽  
Gone With The Wind ◽  
Host Stars ◽  
Radial Velocity Data ◽  
Gaia Dr2

Abstract We demonstrate that planet occurrence does not depend on stellar galactocentric velocity in the Solar neighbourhood. Using Gaia DR2 astrometry and radial velocity data, we calculate 3D galactocentric velocities for 197 090 Kepler field stars, 1647 of which are confirmed planet hosts. When we compare the galactocentric velocities of planet hosts to those of the entire field star sample, we observe a statistically significant (KS p-value  = 10−70) distinction, with planet hosts being apparently slower than field stars by ∼40 km s−1. We explore some potential explanations for this difference and conclude that it is not a consequence of the planet–metallicity relation or distinctions in the samples’ thin/thick disc membership, but rather an artefact of Kepler’s selection function. Non Kepler-host stars that have nearly identical distances, temperatures, surface gravities, and Kepler magnitudes to the confirmed planet hosts also have nearly identical velocity distributions. Using one of these identical non-host samples, we consider that the probability of a star with velocity vtot hosting a planet can be described by an exponential function proportional to $e^{(-v_{\mathrm{tot}}/v_0)}$. Using a Markov Chain Monte Carlo sampler, we determine that v0 >976 km s−1 to 99 per cent confidence, which implies that planets in the Solar neighbourhood are just as likely to form around high-velocity stars as they are around low-velocity stars. Our work highlights the subtle ways in which selection biases can create strong correlations without physical underpinnings.

Pulsed flow modulation of soot production in a laminar jet-diffusion flame

2005 ◽  
Vol 30 (1) ◽  
pp. 1485-1492 ◽  
Author(s):  
O.A. Ezekoye ◽  
K.M. Martin ◽  
F. Bisetti
Keyword(s):  
Diffusion Flame ◽  
Flow Modulation ◽  
Laminar Jet ◽  
Pulsed Flow ◽  
Pulsed Flow Modulation

A Numerical Study on a V-Shaped Laminar Stratified Flame

2005 ◽  
Author(s):  
Hongsheng Guo ◽  
Gregory J. Smallwood ◽  
Cedric Galizzi ◽  
Dany Escudie´
Keyword(s):  
Diffusion Flame ◽  
Numerical Study ◽  
Premixed Flame ◽  
Intermediate Species ◽  
Governing Equations ◽  
Flame Zone ◽  
Rich Region ◽  
Detailed Chemistry ◽  
Stratified Charge ◽  
Diffusion Of Hydrogen

A V-shaped laminar stratified flame was investigated by numerical simulation. The primitive variable method, in which the fully elliptic governing equations were solved with detailed chemistry and complex thermal and transport properties, was used. The results indicate that in addition to the primary premixed flame, the stratified charge in a combustor causes the formation of a diffusion flame. The diffusion flame is located between the primary premixed flame branches. The fuel is fully decomposed and converted to some intermediate species, like CO and H2, in the primary premixed flame branches. Due to the shortage of oxygen, the formed CO and H2 in the fuel rich region of the premixed flame branch is further transported to the downstream until they meet the oxygen from the fuel lean region. This leads to the formation of the diffusion flame. There is an interaction between the diffusion flame and the primary premixed flame branches. The interaction intensifies the burning speed of the primary premixed flame. Both the heat transfer and the diffusion of hydrogen and some radicals cause the interaction. With the increase of the stratified charge region, the diffusion flame zone is enlarged and the interaction is enhanced.

Hydrocarbon species concentrations in nitrogen diluted ethylene-air laminar jet diffusion flames at elevated pressures

2013 ◽  
Vol 34 (1) ◽  
pp. 1035-1043 ◽  
Author(s):  
Ranjith Kumar Abhinavam Kailasanathan ◽  
Emily K. Book ◽  
Tiegang Fang ◽  
William L. Roberts
Keyword(s):  
Diffusion Flames ◽  
Laminar Jet ◽  
Jet Diffusion Flames ◽  
Elevated Pressures
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