Symmetry assessment of an air-blast atomizer spray

This study represents an evaluation of the extent to which conventional and recently introduced modern diagnostics can assess the symmetry of sprays formed by three atomizers of identical design. The conventional diagnostics include sheet-lit photography, which provides a measure of the gross flowfield asymmetries; patternation, which identifies nonuniforaiities in the gross mass flux distribution; and laser diffraction, which reveals variations in line-of-sight measurement of Sauter mean diameter (SMD). The modern diagnostic is laser interfere me try (phase Doppler), which measures local values of droplet size, two-components of droplet velocity, and droplet volume flux. Symmetry is assessed in ambient conditions for four atomizer orientations (0, 60,120, and 180 deg), and comparisons are made between the diagnostic techniques. The results demonstrate that 1) conventionaland modern diagnostics are consistent in the assessment of symmetry, 2) patternation and phase Dopplerare most effective in establishing symmetry of mass flux, and 3) phase Doppler, although more tedious to employ, provides the additional information n cessary to establish the sources of detected asymmetries in terms of non-uniformities in droplet velocites, size distributions, volume flux, and concentration. © 1990, American Institute of Aeronautics and Astronautics, Inc., All rights reserved