Simultaneous 2-D Imaging Measurements of Reaction Progress Variable and OH Radical Concentration in Turbulent Premixed Flames: Instantaneous Flame-Front Structure

2001 ◽  
Vol 167 (1) ◽  
pp. 187-222 ◽  
Author(s):  
YUNG-CHENG CHEN* ◽  
ROBERT W BILGER
Keyword(s):  
Flame Front ◽  
Premixed Flames ◽  
Oh Radical ◽  
Turbulent Premixed Flames ◽  
Reaction Progress ◽  
Progress Variable ◽  
Front Structure ◽  
Radical Concentration ◽  
Turbulent Premixed

Flame Front Structure of Ammonia/air Turbulent Premixed Flames Stabilized in Swirling Flows

2018 ◽  
Vol 2018 (0) ◽  
pp. 0083
Author(s):  
Akihiro Hayakawa ◽  
Masaaki Tsukamoto ◽  
K.D. Kunkuma A. Somarathne ◽  
Taku Kudo ◽  
Hideaki Kobayashi
Keyword(s):  
Flame Front ◽  
Premixed Flames ◽  
Swirling Flows ◽  
Turbulent Premixed Flames ◽  
Front Structure ◽  
Turbulent Premixed

Flame front structure of turbulent premixed flames of syngas oxyfuel mixtures

2014 ◽  
Vol 39 (10) ◽  
pp. 5176-5185 ◽  
Author(s):  
Meng Zhang ◽  
Jinhua Wang ◽  
Jin Wu ◽  
Zhilong Wei ◽  
Zuohua Huang ◽  
...  
Keyword(s):  
Flame Front ◽  
Premixed Flames ◽  
Turbulent Premixed Flames ◽  
Front Structure ◽  
Turbulent Premixed

Measurement of the instantaneous flame front structure of syngas turbulent premixed flames at high pressure

2013 ◽  
Vol 160 (11) ◽  
pp. 2434-2441 ◽  
Author(s):  
Jinhua Wang ◽  
Meng Zhang ◽  
Zuohua Huang ◽  
Taku Kudo ◽  
Hideaki Kobayashi
Keyword(s):  
High Pressure ◽  
Flame Front ◽  
Premixed Flames ◽  
Turbulent Premixed Flames ◽  
Front Structure ◽  
Turbulent Premixed

scholarly journals Assessment of Extrapolation Relations of Displacement Speed for Detailed Chemistry Direct Numerical Simulation Database of Statistically Planar Turbulent Premixed Flames

2021 ◽  
Author(s):  
Nilanjan Chakraborty ◽  
Alexander Herbert ◽  
Umair Ahmed ◽  
Hong G. Im ◽  
Markus Klein
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Premixed Flames ◽  
Turbulent Premixed Flames ◽  
Reaction Progress ◽  
Progress Variable ◽  
Stretch Rate ◽  
Non Linear ◽  
Displacement Speed ◽  
Curvature Dependence

AbstractA three-dimensional Direct Numerical Simulation (DNS) database of statistically planar $$H_{2} -$$ H 2 - air turbulent premixed flames with an equivalence ratio of 0.7 spanning a large range of Karlovitz number has been utilised to assess the performances of the extrapolation relations, which approximate the stretch rate and curvature dependences of density-weighted displacement speed $$S_{d}^{*}$$ S d ∗ . It has been found that the correlation between $$S_{d}^{*}$$ S d ∗ and curvature remains negative and a significantly non-linear interrelation between $$S_{d}^{*}$$ S d ∗ and stretch rate has been observed for all cases considered here. Thus, an extrapolation relation, which assumes a linear stretch rate dependence of density-weighted displacement speed has been found to be inadequate. However, an alternative extrapolation relation, which assumes a linear curvature dependence of $$S_{d}^{*}$$ S d ∗ but allows for a non-linear stretch rate dependence of $$S_{d}^{*}$$ S d ∗ , has been found to be more successful in capturing local behaviour of the density-weighted displacement speed. The extrapolation relations, which express $$S_{d}^{*}$$ S d ∗ as non-linear functions of either curvature or stretch rate, have been found to capture qualitatively the non-linear curvature and stretch rate dependences of $$S_{d}^{*}$$ S d ∗ more satisfactorily than the linear extrapolation relations. However, the improvement comes at the cost of additional tuning parameter. The Markstein lengths LM for all the extrapolation relations show dependence on the choice of reaction progress variable definition and for some extrapolation relations LM also varies with the value of reaction progress variable. The predictions of an extrapolation relation which involve solving a non-linear equation in terms of stretch rate have been found to be sensitive to the initial guess value, whereas a high order polynomial-based extrapolation relation may lead to overshoots and undershoots. Thus, a recently proposed extrapolation relation based on the analysis of simple chemistry DNS data, which explicitly accounts for the non-linear curvature dependence of the combined reaction and normal diffusion components of $$S_{d}^{*}$$ S d ∗ , has been shown to exhibit promising predictions of $$S_{d}^{*}$$ S d ∗ for all cases considered here.

Sign in / Sign up

Export Citation Format

Share Document