Combustion Science and Technology, Vol.141, No.1-6, 37-57, 1999
On the analysis of propane jet flames in mutual interaction
The characteristics of attached non-premixed jet flames in mutual interaction are studied experimentally through the analysis of 1, 3 and 5 propane flames with an individual Reynolds number of 20400. Laser Doppler velocimetry, fine-wire thermometry and chemical species concentration analysis were used to characterise the flame systems, as well as simultaneous acquisition techniques to obtain information on the scalar turbulent behaviour. The results show that, although the turbulent mixing pattern is altered by changes in the mean flow characteristics, the concentration of major chemical species and temperature fields remain qualitatively unaltered at the level of flame interaction studied here. The present results quantify the extent to which turbulent transfer is modified in the interaction zone, though oxygen insufficiency is the controlling mechanism in the propagation of flames in mutual interaction. The analysis shows that turbulent heat fluxes tend to be restricted to the mixing layer where large temperature gradients occur. Otherwise, they exhibit larger component directed along the isotherms, as for single flames. This behaviour suggests that the process of turbulent transport is unaltered at the level of flame interaction considered in this paper.