Quantitative spray analysis of diesel fuel and its emulsions using digital image processing

In the present work, an experimental investigation of spray atomization of different liquids has been carried out. An air-assist atomizer operating at low injection pressures valued (4 and 6 bar) has been used to generate sprays of (diesel fuel, 5, 10, and 15% water-emulsified-diesel), respectively. A Photron-SA4 high speed camera has been used for spray imaging at 2000 fps. 20 time intervals (from 5 to 100 ms with 5 ms time difference) are selected for analysis and comparison. Spray macroscopic characteristics (spray penetration, dispersion, cone angle, axial and dispersion velocities) have been extracted by a proposed technique based on image processing using Matlab, where the maximum and minimum (horizontal and vertical) boundaries of the spray are detected, from which the macroscopic spray characteristics are evaluated. The maximum error of this technique is (1.5% for diesel spray) and a little bit higher for its emulsions.