Influence of molecular transport on burning rate and conditioned species concentrations in highly turbulent premixed flames

Lee，H. C.1,2; Dai，P.1; Wan，M.1,2; Lipatnikov，A. N.3

2021-12-10

10.1017/jfm.2021.794

JOURNAL OF FLUID MECHANICS   影响因子和分区

0022-1120

1469-7645

Apparent inconsistency between (i) experimental and direct numerical simulation (DNS) data that show the significant influence of differential diffusion on the turbulent burning rate and (ii) recent complex-chemistry DNS data that indicate mitigation of the influence of differential diffusion on conditioned profiles of various local flame characteristics at high Karlovitz numbers, is explored by analysing new DNS data obtained from lean hydrogen-air turbulent flames. Both aforementioned effects are observed by analysing the same DNS data provided that the conditioned profiles are sampled from the entire computational domain. On the contrary, the conditioned profiles sampled at the leading edge of the mean flame brush do not indicate the mitigation, but are significantly affected by differential diffusion phenomena, e.g. because reaction zones are highly curved at the leading edge. This observation is consistent with a significant increase in the computed turbulent burning velocity with decreasing Lewis number, with all the results considered jointly being consonant with the leading point concept of premixed turbulent combustion. The concept is further supported by comparing DNS data obtained by allowing for preferential diffusion solely for a single species, either atomic or molecular hydrogen.

combustion flames turbulent reacting flows

SCI ; EI

英语

第一 ; 通讯

NSFC[91752201,51976088] ; Shenzhen Science and Technology Program[KQTD2 0180411143441009] ; Department of Science and Technology of Guangdong Province["2019B21203001","2020B1212030001"] ; Joint Program of Shenzhen Clean Energy Research Institute[L CH-2019011] ; SUSTech[CERI-KY-2019-003]

Mechanics ; Physics

Mechanics ; Physics, Fluids & Plasmas

WOS:000721236300001

CAMBRIDGE UNIV PRESS

20214211039666

Air ; Diffusion ; Hydrogen

Chemical Products Generally:804

ENGINEERING

2-s2.0-85117168257

Scopus

1.Guangdong Provincial Key Laboratory of Turbulence Research and Applications,Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.Guangdong-Hong Kong-Macao Jt. Lab. for Data-Driven Fluid Mechanics and Engineering Applications,Southern University of Science and Technology,Shenzhen,518055,China
3.Department of Mechanics and Maritime Sciences,Chalmers University of Technology,Gothenburg,41296,Sweden

Lee，H. C.,Dai，P.,Wan，M.,et al. Influence of molecular transport on burning rate and conditioned species concentrations in highly turbulent premixed flames[J]. JOURNAL OF FLUID MECHANICS,2021,928.

Lee，H. C.,Dai，P.,Wan，M.,&Lipatnikov，A. N..(2021).Influence of molecular transport on burning rate and conditioned species concentrations in highly turbulent premixed flames.JOURNAL OF FLUID MECHANICS,928.

Lee，H. C.,et al."Influence of molecular transport on burning rate and conditioned species concentrations in highly turbulent premixed flames".JOURNAL OF FLUID MECHANICS 928(2021).