LDV measurements of drop velocity in diesel-type sprays

Drop velocity measurements were made within nonvaporizing, steady, diesel-type, fast dense sprays from single-hole nozzles into compressed nitrogen. The spray gas was n-hexane and velocity data were taken with laser Doppler anemometry. All data were gathered in steady spray conditions. The effects of variations in the gas/liquid density ratios, injection pressures and nozzle geometries were examined in terms of axial and radial drop velocity components. The entrained gas structure was dominant at about 300 nozzle diameters downstream. The injection momentum and nozzle diameter were found to be sufficient data for calculating the steady-state centerline velocity and the tip penetration rate. Further studies of the nonequilibrium developing region up to the 300 diameters distance are necessary for employing the results for engine calculations.