Autoignition Stabilization of a Premixed Jet in Vitiated Coflow

2018 ◽  
Author(s):  
Stephen W. Grib ◽  
Michael W. Renfro
Keyword(s):  
Vitiated Coflow

scholarly journals Global Features of Flame Stabilization in Turbulent Non-premixed Jet Flames in Vitiated Coflow

2015 ◽  
Author(s):  
Aravind Ramachandran ◽  
Daniel A. Tyler ◽  
Parth K. Patel ◽  
Venkateswaran Narayanaswamy ◽  
Kevin M. Lyons
Keyword(s):  
Flame Stabilization ◽  
Jet Flames ◽  
Global Features ◽  
Vitiated Coflow

Visualization of nonpremixed hydrogen jet flame in a vitiated coflow by DNS

2007 ◽  
Vol 10 (2) ◽  
pp. 136-136 ◽  
Author(s):  
Z. Wang ◽  
J. Zhou ◽  
K. Cen
Keyword(s):  
Jet Flame ◽  
Vitiated Coflow

Liftoff behaviors and flame structure of dimethyl ether jet flame in CH4/air vitiated coflow

2019 ◽  
Vol 233 (8) ◽  
pp. 1039-1046 ◽  
Author(s):  
Wei Fu ◽  
Fengyu Li ◽  
Haitao Zhang ◽  
Bolun Yi ◽  
Yanju Liu ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
High Speed ◽  
Equivalence Ratio ◽  
Flame Structure ◽  
High Speed Photography ◽  
Flame Stability ◽  
Jet Flames ◽  
Jet Flame ◽  
Field Temperature ◽  
Vitiated Coflow

The objective of this paper is to investigate the flame structure and liftoff behaviors of a dimethyl ether central jet in CH4/air vitiated coflow in a coflow burner. The liftoff behaviors of dimethyl ether jet flames in the air flow were studied firstly. The flame stability of the burner was analyzed by measuring the flow field temperature with thermocouples. By changing the coflow rate and CH4 equivalence ratio, the liftoff behaviors of dimethyl ether jet flames under different vitiated coflow environments were discussed. The jet flame structure was also analyzed qualitatively by high-speed photography.

Laminar Flame Calculations for Analyzing Trends in Autoignitive Jet Flames in a Hot and Vitiated Coflow

2016 ◽  
Vol 30 (10) ◽  
pp. 8680-8690 ◽  
Author(s):  
Paul R. Medwell ◽  
Michael J. Evans ◽  
Qing N. Chan ◽  
Viswanath R. Katta
Keyword(s):  
Laminar Flame ◽  
Jet Flames ◽  
Vitiated Coflow

A Comparative Computational Fluid Dynamics Study on Flamelet-Generated Manifold and Steady Laminar Flamelet Modeling for Turbulent Flames

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Pravin Nakod ◽  
Rakesh Yadav ◽  
Pravin Rajeshirke ◽  
Stefano Orsino
Keyword(s):  
Laminar Flame ◽  
Turbulent Flame ◽  
Molecular Transport ◽  
Turbulent Flames ◽  
Jet Flames ◽  
Jet Flame ◽  
Air Jet ◽  
Flamelet Generated Manifold ◽  
Vitiated Coflow ◽  
Laminar Flamelet

The laminar flamelet model (LFM) (Peters, 1986, “Laminar Diffusion Flamelet Models in Non-Premixed Combustion,” Prog. Energy Combust. Sci., 10, pp. 319–339; Peters, “Laminar Flamelet Concepts in Turbulent Combustion,” Proc. Combust. Inst., 21, pp. 1231–1250) represents the turbulent flame brush using statistical averaging of laminar flamelets whose structure is not affected by turbulence. The chemical nonequilibrium effects considered in this model are due to local turbulent straining only. In contrast, the flamelet-generated manifold (FGM) (van Oijen and de Goey, 2000, “Modeling of Premixed Laminar Flames Using Flamelet-Generated Manifolds,” Combust. Sci. Technol., 161, pp. 113–137) model considers that the scalar evolution; the realized trajectories on the thermochemical manifold in a turbulent flame are approximated by the scalar evolution similar to that in a laminar flame. This model does not involve any assumption on flame structure. Therefore, it can be successfully used to model ignition, slow chemistry, and quenching effects far away from the equilibrium. In FGM, 1D premixed flamelets are solved in reaction-progress space rather than physical space. This helps better solution convergence for the flamelets over the entire mixture fraction range, especially with large kinetic mechanisms at the flammability limits (ANSYS FLUENT 14.5 Theory Guide Help Document, http://www.ansys.com). In the present work, a systematic comparative study of the FGM model with the LFM for four different turbulent diffusion/premixed flames is presented. The first flame considered in this work is methane-air flame with dilution air at the downstream. The second and third flames considered are jet flames in a coaxial flow of hot combustion products from a lean premixed flame called Cabra lifted H2 and CH4 flames (Cabra, et al., 2002, “Simultaneous Laser Raman-Rayleigh-LIF Measurements and Numerical Modeling Results of a Lifted Turbulent H2/N2 Jet Flame in a Vitiated Coflow,” Proc. Combust. Inst., 29(2), pp. 1881–1888; Lifted CH4/Air Jet Flame in a Vitiated Coflow, http://www.me.berkeley.edu/cal/vcb/data/VCMAData.html) where the reacting flow associated with the central jet exhibits similar chemical kinetics, heat transfer, and molecular transport as recirculation burners without the complex recirculating fluid mechanics. The fourth flame considered is a Sandia flame D (Barlow et al., 2005, “Piloted Methane/Air Jet Flames: Scalar Structure and Transport Effects,” Combust. Flame, 143, pp. 433–449), a piloted methane-air jet flame. It is observed that the simulation results predicted by the FGM model are more physical and accurate compared to the LFM in all the flames presented in this work. The autoignition-controlled flame lift-off is also captured well in the cases of lifted flames using the FGM model.

scholarly journals Simultaneous laser raman-rayleigh-lif measurements and numerical modeling results of a lifted turbulent H2/N2 jet flame in a vitiated coflow

2002 ◽  
Vol 29 (2) ◽  
pp. 1881-1888 ◽  
Author(s):  
R. Cabra ◽  
T. Myhrvold ◽  
J.Y. Chen ◽  
R.W. Dibble ◽  
A.N. Karpetis ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Jet Flame ◽  
Laser Raman ◽  
Vitiated Coflow

Chemical structure of autoignition in a turbulent lifted H2/N2 jet flame issuing into a vitiated coflow

2013 ◽  
Vol 160 (12) ◽  
pp. 2928-2940 ◽  
Author(s):  
Seyed Mohammad Mir Najafizadeh ◽  
Mohammad Taghi Sadeghi ◽  
Rahmat Sotudeh-Gharebagh ◽  
Dirk J.E.M. Roekaerts
Keyword(s):  
Chemical Structure ◽  
Jet Flame ◽  
Vitiated Coflow
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