TY - GEN
T1 - Direct numerical simulation of a turbulent lifted flame
T2 - 19th Australasian Fluid Mechanics Conference, AFMC 2014
AU - Karami, S.
AU - Hawkes, E. R.
AU - Talei, M.
AU - Yu, H.
PY - 2014
Y1 - 2014
N2 - A turbulent lifted slot-jet flame is studied using direct numerical simulation (DNS). A single step chemistry model is employed with a mixture-fraction dependent activation energy to quantitatively reproduce the dependence of laminar burning rate on equivalence ratio that is typical of hydrocarbon fuels. It is observed that the leading flame edge exhibits a single branch close to the stoichiometric mixture fraction iso-surface, rather than a tribrachial structure. The flame edge has a complex, highly convoluted structure suggesting it can burn at speeds that are much faster than SL. There is no evidence of a rich inner premixed flame or detached diffusion flame islands, in contrast with the observation in the previous DNS studies of hydrogen flames. On average, the streamwise velocity balances the streamwise flame propagation, confirming that flame propagation is the basic stabilisation mechanism. The analysis of the flow and propagation velocities reveal an elliptical pattern of flame motion around the average stabilisation point. Visualisation of the flame suggests that this motion is connected with the passage of large eddies.
AB - A turbulent lifted slot-jet flame is studied using direct numerical simulation (DNS). A single step chemistry model is employed with a mixture-fraction dependent activation energy to quantitatively reproduce the dependence of laminar burning rate on equivalence ratio that is typical of hydrocarbon fuels. It is observed that the leading flame edge exhibits a single branch close to the stoichiometric mixture fraction iso-surface, rather than a tribrachial structure. The flame edge has a complex, highly convoluted structure suggesting it can burn at speeds that are much faster than SL. There is no evidence of a rich inner premixed flame or detached diffusion flame islands, in contrast with the observation in the previous DNS studies of hydrogen flames. On average, the streamwise velocity balances the streamwise flame propagation, confirming that flame propagation is the basic stabilisation mechanism. The analysis of the flow and propagation velocities reveal an elliptical pattern of flame motion around the average stabilisation point. Visualisation of the flame suggests that this motion is connected with the passage of large eddies.
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M3 - Conference contribution
AN - SCOPUS:85031984380
T3 - Proceedings of the 19th Australasian Fluid Mechanics Conference, AFMC 2014
BT - Proceedings of the 19th Australasian Fluid Mechanics Conference, AFMC 2014
PB - Australasian Fluid Mechanics Society
Y2 - 8 December 2014 through 11 December 2014
ER -