Contribution à l'étude des instabilités interfaciales liquide-gaz en atomisation assistée et taille de gouttes

The study of assisted atomisation interest many industrial sectors in particular, the engines manufacturing in aeronautics and in aerospace. Lndeed, the optimization of the liquid fuel pulverization by a fast gas jet is one of the key issues which determine the efficiency of these engines. Experimental results shown that, on a large broad range of parameter, the most amplified axial instability is Kelvin-Helmholtz type with a wavelength controlled by the thickness of the gas vorticity layer. The ligaments which develop at the peaks of the axial waves are stretched and broken into drops. The analysis and measurements on the transverse instability shows it is a Rayleigh-Taylor type. The transverse wavelength depends on the physical parameters of the fluids, the thickness of the gas vorticity layer and the number of Weber. The fog of drops has been characterized using an optical probe with conical head. Finally some techniques are proposed for the improvement of assisted atomization