scholarly journals Analysis of Turbulent Burning Velocity of Spherically Propagating Premixed Flame with Effective Turbulence Intensity

2012 ◽  
Vol 7 (4) ◽  
pp. 507-521 ◽  
Author(s):  
Akihiro HAYAKAWA ◽  
Yukito MIKI ◽  
Yukihide NAGANO ◽  
Toshiaki KITAGAWA
Keyword(s):  
Turbulence Intensity ◽  
Burning Velocity ◽  
Premixed Flame ◽  
Turbulent Burning Velocity

Technical Note: The importance of turbulence intensity, eddy size and flame size in spark ignited, premixed flame growth

1997 ◽  
Vol 211 (1) ◽  
pp. 83-86 ◽  
Author(s):  
D S-K Ting ◽  
M. D. Checkel
Keyword(s):  
Turbulence Intensity ◽  
Burning Velocity ◽  
Lewis Number ◽  
Technical Note ◽  
Premixed Flame ◽  
Mean Square ◽  
Laminar Burning Velocity ◽  
The Mean ◽  
Turbulent Burning Velocity ◽  
Velocity Turbulence

The effects of laminar burning velocity, turbulence intensity, flame size and eddy size on the turbulent burning velocity of a premixed growing flame were experimentally separated in a 125 mm cubical chamber with lean methane-air mixtures spark ignited at 1 atm and 300 K. The turbulence was up to 2 m/s with 1 to 4 mm Taylor microscale. For the near unity Lewis number and near zero Markstein number mixture considered here, the turbulent burning velocity, St, can be approximated as: St = Sl + Cd(r/λ)u′, where Sl is the laminar burning velocity, r is the mean flame radius, λ is the Taylor microscale, u′ is the root mean square (r.m.s.) turbulence intensity and Cd is a constant of the order 0.02.

scholarly journals 804 Turbulent Burning Velocity of Spherically Propagating Premixed Flame based on Mean Progress Variable

2013 ◽  
Vol 2013.66 (0) ◽  
pp. 241-242
Author(s):  
Akihiro HAYAKAWA ◽  
Toshihiko KUBO ◽  
Taiki TSUKAMOTO ◽  
Yukihide NAGANO ◽  
Toshiaki KITAGAWA
Keyword(s):  
Burning Velocity ◽  
Premixed Flame ◽  
Progress Variable ◽  
Turbulent Burning Velocity

The influence of laminar burning velocity on the structure and propagation of turbulent flames

1979 ◽  
Vol 367 (1731) ◽  
pp. 485-502 ◽  
Keyword(s):  
Turbulence Intensity ◽  
Burning Velocity ◽  
Diffusion Mechanism ◽  
Turbulent Flames ◽  
Laminar Burning Velocity ◽  
Premixed Turbulent Flames ◽  
Region Model ◽  
High Turbulence ◽  
Model Region ◽  
Turbulent Burning Velocity

An experimental study of the influence of laminar burning velocity on the structure and propagation of duct-confined premixed turbulent flames has been carried out. Propane, acetylene and hydrogen were used as fuels to vary the laminar burning velocity in the range from 20 to 280 cm/s. These experiments fully verify the three region model (region 1: u ' < 2 S L , η > δ L ; region 2: u ' ≈ 2 S L , η ≈ δ L to η ≫ δ L ; region 3: u ' > 2 S L , η < δ L ) of turbulent flames proposed earlier by Ballal & Lefebvre. Since a large increase in the laminar burning velocity has a stabilizing influence it is possible to suppress the ‘instability’ of region 1 and the ‘eddy entrainment’ of region 3. The ‘turbulent diffusion’ mechanism then becomes solely dominant, and the flame shows a ‘jet-like’ behaviour. For such a flame (i) both the burning velocity and flame turbulence intensity are independent of scale, (ii) the equations developed by Karlovitz and Ballal for regions of stable combustion accurately predict all the experimental data on turbulent burning velocity and flame turbulence, respectively, and (iii) the laminar burning velocity remains an important parameter of flame propagation even at very high turbulence intensity. Finally the important role of shear-generated turbulence and the ability of the flame either to dampen or to generate additional turbulence has been fully confirmed.

Experimental Study of Turbulent Burning Velocity of Premixed Biogas Flame

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Ahmad Ayache ◽  
Madjid Birouk
Keyword(s):  
Turbulence Intensity ◽  
Equivalence Ratio ◽  
Fossil Fuels ◽  
Isotropic Turbulence ◽  
Burning Velocity ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Velocity Versus ◽  
Carbon Dioxide Co2 ◽  
Turbulent Burning Velocity

Biogas is a renewable source of energy produced by anaerobic digestion of organic material and composed mainly of methane (CH4) and carbon dioxide (CO2). Despite its lower heating value, biogas can still replace fossil fuels in several engineering stationary power generation and other industrial applications. Although numerous published studies were devoted to advance our understating of biogas combustion, experimental data of some parameters such as turbulent burning velocity (St) under certain operating conditions is still lacking. The present study aims to experimentally determine biogas turbulent burning velocity under normal temperature and pressure conditions. Turbulent premixed biogas–air flame was ignited at the center of a 29 L fan-stirred spherical combustion chamber of nearly homogeneous and isotropic turbulence. Test conditions consisted of varying turbulence intensity and biogas surrogate composition. Outwardly propagating biogas flames were tracked and imaged using Schlieren imaging technique. The results showed that, by increasing turbulence and reducing methane percentage in the surrogate, the flammability of the mixture shrinked. In addition, the curve fits of biogas turbulent burning velocity versus the equivalence ratio exhibited two different trends. The peak of turbulent burning velocity shifted away from nearly lean equivalence ratio toward the stoichiometric at a fixed turbulence intensity and higher CH4 percentage in the surrogate. However, for the same biogas surrogate composition, the peak of turbulent burning velocity shifted away from stoichiometric toward leaner equivalence ratio with increased turbulence intensity.

scholarly journals Turbulent burning velocity of ammonia/oxygen/nitrogen premixed flame in O2-enriched air condition

Fuel ◽  
2020 ◽  
Vol 268 ◽  
pp. 117383 ◽  
Author(s):  
Yu Xia ◽  
Genya Hashimoto ◽  
Khalid Hadi ◽  
Nozomu Hashimoto ◽  
Akihiro Hayakawa ◽  
...  
Keyword(s):  
Burning Velocity ◽  
Premixed Flame ◽  
Turbulent Burning Velocity
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