Liquid film breakup of three different geometrical variants of a planar prefilming airblast atomizer have been studied using advanced Particle Tracking Velocimetry (PTV) coupled with ligament tracking. In addition to the variation in geometry, liquids with different physical properties (surface tension, viscosity) have been tested. The liquid mass flow rate and mean air velocities were varied over a wide range of test conditions. A post-processing algorithm was developed to capture the ligament and droplet sizes and their velocities. For the test conditions investigated, it was observed that the mean air velocity and the thickness of the atomizing edge are the key parameters that influence the breakup process. From the database of test cases, correlations for the liga-ment breakup frequency, Sauter mean diameter and mean velocity of the primary droplets are derived. |