Experimental Study of Liquid Fuel Spray Characteristics and Atomization - A Review

Spray atomization is nothing but the conversion of bulk liquid into a large number of small droplets (i.e. a spray) which generally occurs when we inject fuel through a nozzle. The combustion performance and emissions are mainly influenced by the atomization, evaporation and velocity of the fuel droplets and mixing of fuel with air. The major challenge is to get control on NOx and CO emission which minimizes the efficiency of combustion process, temperature distribution etc. Laser diagnostics system is now emerging as a powerful tool for the investigation of fuel characteristics. Proper atomization of fuel always leads to complete combustion. In this study the effect on fuel spray characteristics such as SMD, velocity of fuel droplets, vorticity, centricity, air entrainment by changing the injection pressure and mass flow rate was studied with the help of laser diagnostics system. Sauter Mean Diameter (SMD) is average droplet diameter. Co-flow means addition of excess air to the surrounding of spray to enhance the air entrainment to get proper/complete combustion of fuel droplets. Therefore it becomes extremely important to understand the fuel spray dispersion under different conditions of pressure and fuel flow rate.