Turbulent non-premixed ethanol-air flame experimental study using laser diagnostics

A turbulent non-premixed ethanol spray flame is characterized through experiments using planar laser-induced fluorescence (PLIF) of the OH radical and Mie scattering of fuel droplets distribution. The spray burner generates a stable flame with the use of a bluff body. The OH fluorescence intensity demarcates the reaction zone. Initially, different water spray loadings are compared, allowing determining the spray characteristics. Then, two combustion situations are studied emphasizing the instantaneous distribution of the droplet cloud with respect to the reaction zone. The instantaneous and average OH images allow identifying local flame extinction. In the first situation, the spray is surrounded by flame, and complete droplet evaporation occurs before combustion, which represents a classical behaviour. In the second situation, droplets interact strongly with the combustion process leading to an unusually large extinction.