LASER-DIFFRACTION MEASUREMENT OF NONSPHERICAL DROP SPRAYS

WOS:000333720200002International audienceThe objective of the present experimental and analytical investigation is to acquire a better understanding and appreciation of the volume-based drop-diameter distribution measured by laser diffraction technique (LDT) when probing sprays with a significant rate of nonspherical drops. Experiments are performed on sprays of several liquids with a LDT and an image analyzing technique (IAT). IAT is used to attest to and quantify the average nonsphericity of the drops. The LDT diameter distribution characterizes an equivalent system of spherical drops that would produce the same forward light scattered pattern as the one recorded. By modeling this distribution with a three-parameter generalized gamma function according to a recent optimization procedure, it is demonstrated that drop shape influences the fractal characteristic of the LDT distribution in the small diameter region. This suggests that LDT analyzes deformed drops as clusters of smaller drops. Thus, the small drop population of the LDT equivalent system contains information of the actual small drop population and on the shape of the actual drops. The presence of deformed drops manifest by an extended tail of the LDT distribution in the large diameter region also, which results in specific mean diameter series as suspected in previous investigations