Abstract
There is a need for more and more comprehensive examination of injected fuel sprays in order to diminish the exhaust emission and to reduce the fuel consumption of piston internal combustion engines. Laser beam based measuring methods, offering accurate determination of spray parameters and providing real time results, become increasingly significant. The LDV (Laser Doppler Velocimeter) and PDPA (Phase Doppler Particle Analyzer) methods, used for simultaneous investigation of the velocity and size of droplets, are discussed in this paper. The results of measurements of the fuel spray produced by selected types of low - pressure, air - assist petrol injectors, injectors of CI engines and injectors of Common Rail system will be presented. The measurements were carried out using a constant volume chamber securing optical access to the spray of atomized fuel. The results were processed mainly to determine the effect of pressure on the structure of sprays of injected fuel.