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Spatial profiles of the droplet velocities and sizes from a steady state ‘Diesel type’ spray exhausting into open atmosphere have been performed using a Phase Doppler Anemometer. An analysis of the size selective behavior of the droplets has been carried out by dividing the droplets into five size classes, and the comparisons between the droplets behavior and the continuous phase behavior could provide interesting topics. But the measurements of the gaseous phase velocity in and outside such a spray are limited. A technique taking into account these velocities has then been developed using a droplet tagging method. Tagged droplets with a fluorescent dye, while passing through the two-components LDA probe volume, emit light at the fluorescent wavelength, plus the Mie scattered light.

We propose here an experimental method, based on two-point Laser Doppler anemometry which makes possible direct measurement of spatial velocity correlation function from which the integral and Taylor's length scales are calculated. The technique has been carefully checked on simple flows and we present here a first application in a steady flow simulating the induction stroke of an internal combustion engine. Profiles of integral length scale, Taylor length scale and dissipation rate are determined at several distances from the cylinder head. The effect of valve lift is also taken into account.