Numerical study on the effects of ozone addition on the development of laminar premixed flames and emissions for methane and propane in a co-flow configuration

Energy ◽  
2021 ◽  
pp. 122744
Author(s):  
Gianfranco Scribano ◽  
Xinwei Cheng ◽  
Manh-Vu Tran
Keyword(s):  
Numerical Study ◽  
Premixed Flames ◽  
Flow Configuration ◽  
Ozone Addition

Structure and propagation speeds of turbulent premixed flames—A numerical study

1991 ◽  
Vol 83 (1-2) ◽  
pp. 155-173 ◽  
Author(s):  
Sherif H. El Tahry ◽  
Christopher Rutland ◽  
Joel Ferziger
Keyword(s):  
Numerical Study ◽  
Premixed Flames ◽  
Turbulent Premixed Flames ◽  
Turbulent Premixed

Numerical Simulations of Turbulent Mixing and Autoignition of Hydrogen Fuel at Reheat Combustor Operating Conditions

2011 ◽  
Author(s):  
Elizaveta Ivanova ◽  
Berthold Noll ◽  
Peter Griebel ◽  
Manfred Aigner ◽  
Khawar Syed
Keyword(s):  
Natural Gas ◽  
Numerical Simulations ◽  
Flue Gas ◽  
Turbulent Mixing ◽  
Turbulence Modeling ◽  
Numerical Study ◽  
Operating Conditions ◽  
Fuel Blend ◽  
Flow Configuration ◽  
Modeling Methods

Turbulent mixing and autoignition of H2-rich fuels at relevant reheat combustor operating conditions are investigated in the present numerical study. The flow configuration under consideration is a fuel jet perpendicularly injected into a crossflow of hot flue gas (T > 1000K, p = 15bar). Based on the results of the experimental study for the same flow configuration and operating conditions two different fuel blends are chosen for the numerical simulations. The first fuel blend is a H2/natural gas/N2 mixture at which no autoignition events were observed in the experiments. The second fuel blend is a H2/N2 mixture at which autoignition in the mixing section occurred. First, the non-reacting flow simulations are performed for the H2/natural gas/N2 mixture in order to compare the accuracy of different turbulence modeling methods. Here the steady-state Reynolds-averaged Navier-Stokes (RANS) as well as the unsteady scale-adaptive simulation (SAS) turbulence modeling methods are applied. The velocity fields obtained in both simulations are directly validated against experimental data. The SAS method shows better agreement with the experimental results. In the second part of the present work the autoignition of the H2/N2 mixture is numerically studied using the 9-species 21-steps reaction mechanism of O’Conaire et al. [1]. As in the reference experiments, autoignition can be observed in the simulations. Influences of the turbulence modeling as well as of the hot flue gas temperature are investigated. The onset and the propagation of the ignition kernels are studied based on the SAS modeling results. The obtained numerical results are discussed and compared with data from experimental autoignition studies.

scholarly journals Experimental and Numerical Study of the Coanda Effect Used to Reduce Self-Sustained Tones

2002 ◽  
Author(s):  
C. Allery ◽  
S. Gue´rin ◽  
A. Hamdouni ◽  
A. Sakout
Keyword(s):  
Horizontal Plane ◽  
Numerical Study ◽  
Coanda Effect ◽  
Inclined Plane ◽  
Flow Configuration ◽  
Large Hysteresis ◽  
Dimensional Dynamical System ◽  
Coandǎ Effect ◽  
Low Dimensional ◽  
Proper Orthogonal

We present in this paper an experimental and numerical study about the Coanda effect which causes the sudden reattachment of a jet to an inclined plane. This phenomenon induces a large hysteresis loop, which can be used to reduce the noise produced by an airflow crossing two diaphragms in tandem inside a duct. The angle of the inclined wall with horizontal plane and the flow velocity are the two main parameters studied here. With the aim of doing optimal control, we propose to construct for this flow configuration a low-dimensional dynamical system with a basis issued from a Proper Orthogonal Decomposition.

scholarly journals Numerical study of the superadiabatic flame temperature phenomenon in hydrocarbon premixed flames

2002 ◽  
Vol 29 (2) ◽  
pp. 1543-1550 ◽  
Author(s):  
Fengshan Liu ◽  
Hongsheng Guo ◽  
Gregory J. Smallwood ◽  
Ömer L. Gülder
Keyword(s):  
Numerical Study ◽  
Flame Temperature ◽  
Premixed Flames

The Effects of Fuel and Air Mixtures in Non-Premixed Combustion for a Bluff-Body Flame

2015 ◽  
Author(s):  
Lu Chen ◽  
Francine Battaglia
Keyword(s):  
Bluff Body ◽  
Numerical Study ◽  
Premixed Flames ◽  
Turbulence Models ◽  
Premixed Combustion ◽  
Oh Radicals ◽  
No Emission ◽  
Combustion Modeling ◽  
High Specific Heat ◽  
Low Levels

The bluff-body stabilized flame is used in a numerical study of the non-premixed flames. This paper shows numerical investigations on the effects of hydrogen compositions and nonflammable diluent mixtures on the combustion and NO emission characteristics of syngas non-premixed flames for a bluff-body burner. The assessment of turbulent non-premixed combustion modeling techniques is presented and discussed. The simulations study the predictive capabilities of five turbulence models and are compared with the experiments of Correa and Gulati [1] for a non-premixed flame of 27.5%CO/32.3%H2/40.2%N2 and air. The Realizable k-ε and the Reynolds Stress (RSM) models were found to perform the best. Based on this, a numerical study to assess the effects of hydrogen component on syngas non-premixed combustion was performed. As a result, hydrogen addition caused the radial velocity and strain rate to decrease, which was important for mixing to decrease NO. Also, the effectiveness of nonflammable diluent mixtures, including N2, CO2 and H2O, were characterized in terms of the ability to reduce NO emission in syngas non-premixed flames. Results indicated that CO2 was the most effective diluent to reduce NO emission and H2O was more effective than N2. CO2 diluent produced low levels of OH radical, which makes CO2 the most effective diluent. Although H2O increased OH radicals, it was still effective to decrease the thermal NO because of its high specific heat.

A Numerical Study on the Effect of Water Addition on NO Formation in Counterflow CH4/Air Premixed Flames

2005 ◽  
Author(s):  
Hongsheng Guo ◽  
Stuart W. Neill ◽  
Gregory J. Smallwood
Keyword(s):  
Numerical Study ◽  
Temperature Drop ◽  
Flame Temperature ◽  
Premixed Flames ◽  
Chemical Effect ◽  
Water Addition ◽  
Detailed Chemistry ◽  
Effect Of Water ◽  
No Formation ◽  
The Rich

The effect of water addition on NO formation in counterflow CH4/air premixed flames was investigated by numerical simulation. Detailed chemistry and complex thermal and transport properties were employed. The results show that the addition of water to a flame suppresses the formation of NO primarily due to the flame temperature drop. Among a lean, a stoichiometric and a rich premixed flame, the effectiveness of water addition is most significant for the stoichiometric flame and least for the rich flame, since the dominant NO formation mechanism varies. The addition of water also reduces the formation of NO in a flame because of chemical effect that increases the concentration of OH, while reduces the concentrations of O and H. Compared to the stoichiometric flame, the chemical effect is intensified in the lean and rich flames.

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