Abstract
This paper describes an experimental bench for a non intrusive characterisation of fuel sprays, developed by AEA for SIEMENS AUTOMOTIVE, in collaboration with Siemens R&D staff and Perugia University researchers. This application was developed to test different fuel injectors types, in particular conventional gasoline low pressure injectors as more recent GDI and PIEZO injectors up to 250 bar. The injectors can be tested in air or in a test chamber at nitrogen pressures up to 20 bar. Two different techniques have been implemented to obtain the spray images: the conventional Shadowgraphy technique based on a back-light stroboscopic lamp; the Mie-scattering technique based on a Nd-YAG laser sheet. An image analysis software application has been developed to characterise the spray, by determining the geometrical characteristics of the spray in terms of penetration, bend angle and cone angle. It is also possible to obtain the probability of presence of the spray in a region of the space. In the paper, the experimental rig assembling is described, along with the analysis tool implementation. Examples of operation and typical results are also presented.