Closure Relations for Fluxes of Flame Surface Density and Scalar Dissipation Rate in Turbulent Premixed Flames

Fluids

Shinnosuke Nishiki¹  AndreiN. Lipatnikov²  Tatsuya Hasegawa³ 

[1] Department of Mechanical Engineering, Kagoshima University, Kagoshima 890-0065, Japan;Department of Mechanics and Maritime Sciences, Chalmers University of Technology, 412 96 Gothenburg, Sweden;Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan;

关键词: turbulent flame;    premixed turbulent combustion;    countergradient transport;    flame surface density;    scalar dissipation rate;    modeling;    direct numerical simulations;   

DOI  :  10.3390/fluids4010043

来源: DOAJ

【 摘 要 】

In this study, closure relations for total and turbulent convection fluxes of flame surface density and scalar dissipation rate were developed (i) by placing the focus of consideration on the flow velocity conditioned to the instantaneous flame within the mean flame brush and (ii) by considering the limiting behavior of this velocity at the leading and trailing edges of the flame brush. The model was tested against direct numerical simulation (DNS) data obtained from three statistically stationary, one-dimensional, planar, premixed turbulent flames associated with the flamelet regime of turbulent burning. While turbulent fluxes of flame surface density and scalar dissipation rate, obtained in the DNSs, showed the countergradient behavior, the model predicted the total fluxes reasonably well without using any tuning parameter. The model predictions were also compared with results computed using an alternative closure relation for the flame-conditioned velocity.

【 授权许可】

Unknown