Simultaneous measurement of evaporating fuel spray using laser induced exciplex fluorescence

A macroscopic analysis of experimental measurements offuel sprays penetration on evaporating conditions using the Laser Induced Fluorescence Planar technique is presented. A pure fuel and tracers have been used to determine the two-phase process of the spray by characterizing the wavelengths they display when excited by a laser beam. An experimental set-up based on a single cylinder engine [1, 2], an Nd:YAG laser, an image acquisition system and a system of injection common rail have been used to carry out the experimental processes. Experimental results show the behaviour of the vapour phase and liquid phase in the spray under different thermodynamic conditions and injection parameters in the combustion chamber, particularly the work-fluid density and the injection pressure were observed. The measurement of these parameters is of interest to design the combustion chamber geometry and the piston bowl features of modern direct injection Diesel engines. In particularly, the sschematic diagram and main components of the equipment, cross-sectional view of the cylinder head, experimental layout of PLIEF imaging tests and images, examples of the liquid phase and vapour phase penetration, maximum penetration of the liquid and vapour phase as function of the work fluid density, Maximum penetration of the phase as function of the work fluid density, maximum penetration of the liquid and vapour phase as function of the injection pressure are presented in the paper.