EXPERIMENTAL INVESTIGATION OF HIGH PRESSURE DIESEL INJECTION IN PRESENCE OF SWIRL

Abstract

The droplet-size distribution in sprays is one of the important factors affecting the characteristics of spray combustion and pollutant formation in diesel engines. The understanding and characterization of high pressure fuel spray is central to fuel efficient, diesel engines. Sauter mean diameter (SMD) and droplet size distribution are important elements of spray characteristics. An exhaustive .literature review was done to understand the spray•characteristics and to study the parameters affecting droplet-size distribution. From the literature, it is observed that the droplet-size distribution of the diesel spray depends on the fuel properties, injection parameters, nozzle geometry, air density and air motion. Most of 'the correlations available in the literature are based on - experimental -observations for the atomization characteristics of the diesel spray and are derived without taking into consideration the effect of, air motion. For accurate prediction of fuel-air mixing in diesel engines, prediction of droplet concentration and droplet-size distribution is one' of the important steps. The present study is aimed at studying the effect of various parameters on droplet-size distribution and to develop empirical correlations for prediction of droplet-size, distribution and distribution of spray concentration based on experimental data., 111 In present study, the spatial and temporal variation of droplet-size distribution and spray concentration is measured at various transverse air velocities and air densities for hole nozzle of an automotive engine using laser diffraction technique. The injection characteristics i.e. instantaneous injection pressures and rates of injection are also measured by TSNITA chamber technique. The correlations are developed based on experimental results .using statistical regression analysis for prediction of droplet volume concentration (spray density) and Rosin- Rammler droplet size distribution in deflected.