Phase doppler anemometry measurements of diesel spray

Phase Doppler Anemometry (PDA) is a non-intrusive optical technique used to simultaneously determine the droplet size and velocity at a specific point in the spray. Focusing the control volume at different locations within the measurement zone allows the characterisation of both temporal and spatial profile of spray behaviour. The investigation outlined in this paper comprises the analysis of particle size and velocity using the PDA technique (Dantec 1-D PDA measurement system) applied to a dense spray. This spray was produced by a common-rail electronically controlled diesel injection system. Three feeding pressures (1000, 1400 and 1600 bar) at different in-cylinder conditions were chosen to characterise the spray. The fundamental principles of PDA will be described in this paper together with description and of the main difficulties in application of the technique in the diesel spray environment.