Liquid Spray Characterization Using Phase /Doppler Technique.(Dept.M)

Abstract

Spray characteristics of three liquids, water. diesel fuel, and kerosene. sprayed vertically downward in a transparent squared section rube which is accessed with an exhauster through Doppler Particle a pressure swirl atomizer, have been evaluated by means of Phase Analyzer (PIDPA) system. The experimental apparatus is accessed with a traversing system which enables to make complete scan. radially and axially, for the spray cone. Different pressure differentials across the nozzle are applied to study their effect on spray characteristics. Measurements of drop let mean diameter, droplet size distribution . droplet mean velocity, liquid volume flux and droplet number density have been carried out. Experimental results showed that the droplet size increases and droplet axial mean velocity decreases as the radial distance from spray axis increases. Also, as the axial distance from the nozzle plane increases. the droplet axial mean velocity decreases for the used liquids. the droplet mean diameter and liquid volume flux decrease for both water and diesel fuel but deviation is observed for kerosene. and the droplet number density increases for all used liquids. As the pressure differential across the nozzle increases, both droplet mean diameter and liquid volume flux decreases. and the axial mean velocity increases. for the used liquids. Data analysis shows that the mass median diameter to Sauter mean diameter ratio is affected by the pressure differential across the nozzle, and by Rosin-Rammler exponent, which is a measure of the width of distribution . kerosene, always. has the smallest drop let mean diameter, and water, in most of cases. has the largest mean diameter. Sometimes, diesel fuel competes water having the largest mean diameter.