Influence of fuel temperature on atomization performance of pressure-swirl atomizers

The influence of fuel temperature on mean drop size and drop-size distribution is examined for aviation gasoline and diesel oil using three pressure-swirl simplex nozzles. Spray characteristics are measured over wide ranges of fuel injection pressure and ambient air pressure using a Malvern spray analyzer. Fuel temperatures are varied from 20+ 50°C. Over this range of temperature, the overall effect of an increase in fuel temperature is to reduce the mean drop size and broaden the drop-size distribution in the spray. Generally, it is found that the influence of fuel temperature on mean drop size is far more pronounced for diesel oil than for gasoline. For both fuels, the beneficial effect of higher fuel temperatures on atomization quality is sensibly independent of ambient air pressure.