Performance of conditional source-term estimation model for LES of turbulent premixed flames in thin reaction zones regime

2015 ◽  
Vol 35 (2) ◽  
pp. 1367-1375 ◽  
Author(s):  
Nasim Shahbazian ◽  
M. Mahdi Salehi ◽  
Clinton P.T. Groth ◽  
Ömer L. Gülder ◽  
W. Kendal Bushe
2000 ◽  
Vol 24 (1A) ◽  
pp. 33-44
Author(s):  
E. Lee ◽  
K.Y. Huh

The Coherent Flamelet Model (CFM) is applied to symmetric counterflow turbulent premixed flames studied by Kostiuk et al. The flame source term is set proportional to the sum of the mean and turbulent rate of strain while flame quenching is modeled by an additional multiplication factor to the flame source term. The turbulent rate of strain is set proportional to the turbulent intensity to match the correlation for the turbulent burning velocity investigated by Abdel-Gayed et al. The predicted flame position and turbulent flow field coincide well with the experimental observations. The relationship between the Reynolds averaged reaction progress variable and flame density seems to show a wrong trend due to inappropriate modeling of the sink and source term in the transport equation.


Computation ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 26 ◽  
Author(s):  
Shokri Amzin ◽  
Mariusz Domagała

In turbulent premixed flames, for the mixing at a molecular level of reactants and products on the flame surface, it is crucial to sustain the combustion. This mixing phenomenon is featured by the scalar dissipation rate, which may be broadly defined as the rate of micro-mixing at small scales. This term, which appears in many turbulent combustion methods, includes the Conditional Moment Closure (CMC) and the Probability Density Function (PDF), requires an accurate model. In this study, a mathematical closure for the conditional mean scalar dissipation rate, <Nc|ζ>, in Reynolds, Averaged Navier–Stokes (RANS) context is proposed and tested against two different Direct Numerical Simulation (DNS) databases having different thermochemical and turbulence conditions. These databases consist of lean turbulent premixed V-flames of the CH4-air mixture and stoichiometric turbulent premixed flames of H2-air. The mathematical model has successfully predicted the peak and the typical profile of <Nc|ζ> with the sample space ζ and its prediction was consistent with an earlier study.


2019 ◽  
Vol 208 ◽  
pp. 63-78 ◽  
Author(s):  
Wu Jin ◽  
Scott A. Steinmetz ◽  
Mrinal Juddoo ◽  
Matthew J. Dunn ◽  
Zuohua Huang ◽  
...  

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