ICLASS 06-151 COMPARISON OF PARTICLE SIZE AND VELOCITY INVESTIGATIONS IN SPRAYS CARRIED OUT BY MEANS OF DIFFERENT MEASUREMENT TECHNIQUES

Measurement techniques for simultaneous droplet sizing and velocimetry are compared in resp ect of their applicability and inherent limitations. A det ailed discussion of the results requires specific correction s f the data to compensate for the inherent effects of the diff rent sampling methods, i.e. flux-sensitive and concentra tion dependent. Among others, these incorporate a correcti on of the diameter-velocity relationship for the flux-dep endent Phase Doppler Interferometry (PDI) and a depth of f ield correction for Shadow Imaging. It is demonstrated, that flux-dependent methods lik e PDI and the concentration imaging techniques Interferom tric Mie Imaging (IMI) and Shadowgraphy yield consistent results at various positions in a dilute spray. While PDI is able to resolve a bi-modal droplet size distributio n, IMI tends to pronounce larger droplets. With respect to the application in the dense sprays for automotive applic ations and high-pressure and elevated temperature conditio s, Shadowgraphy is considered to be least sensitive to beam-steering and multiple light scattering.