Structure of a non-premixed flame interacting with counterrotating vortices

• Published in: Symposium, International, on Combustion International, on Combustion, 1996, Vol.26 (1), p.1079-1086
• Main Authors: Thévenin, D., Rolon, J.C., Renard, P.H., Kendrick, D.W., Veynante, D., Candel, S.
• Format: Article
• Language: English
• ISSN: 0082-0784
• DOI: 10.1016/S0082-0784(96)80322-5

Flame-vortex interactions constitute a problem of fundamental interest for turbulent combustion modeling. Flames rolled up in vortices may also be found in a variety of practical applications. Results of a theoretical and experimental study concerning the interaction of vortical structures with a nonpremixed flame are reported. Numerical computations are performed using direct numerical simulation with detailed models for the chemistry, transport processes, and thermodynamical properties. The accuracy of the time-dependent computation has been carefully checked. Due to the cost of the simulations, the calculations were carried out on parallel vector supercomputers. The experimental results are obtained using a steady, nonpremixed counterflow flame with hydrogen as the fuel. A vortex ring, which is generated from a tube installed in one of the combustor nozzles, impinges on the flame. A detailed description of the numerical results is given, showing a global enhancement of the chemical reactions due to the interaction with the vortices. Qualitative comparison between theoretical and experimental results concerning the flame structure during the interaction process are also described. Numerical results are used to complement the experimental measurements and help explain typical features of the roll-up, while experimental results may be employed to assess the validity of the computational procedure.