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A series of experimental studies has been conducted to make clear the characteristics of a new type of diesel sprays, which are injected from an elliptic nozzle. The spray counter has been visualized by Laser induced fluorescence method. An instrument based on the Laser Diffraction principle was used to detect the droplet size of the sprays and a LDV system was used to measure the air entrainment. The fuel was provided from an accumulator pressurized with nitrogen. Four elliptic nozzles with different aspect ratio of the hole from 1.43 to 4.5 were tested. The equivalent diameter of the hole was about 0.33 to 0.36 mm. The injection pressure was 10 MPa. For comparison, a circular spray was also measured. The results show that the spray angle of elliptic sprays is much larger than that of the circular spray while the SMD of elliptic sprays is smaller than that of the circular spray at same experimental condition.

The results of an experimental study on the atomization and evaporation processes of Diesel fuel sprays by using the multi pulsed Gabor and Leith-Upatnieks laser holographic technique are reported in this paper. The spacial distributions of Sauter Mean Diameter and volume density in the spray have been obtained from Gabor hologram. With the help of Triple Pulsed Gabor Laser Holography, the velocity distributions of droplets in the leaner region of the sprays in room temperature enviornment has been observed. White light was adopted to reconstruct the Leith-Upatnieks image plane hologram so as to eliminate the speckle noise of phase type hologram. With this method, the Comet like tail vapor following behind the droplets at the edge of a spray in high temperature enviornment could also be observed. Based on the experimental results, the atomization and evaporation processes of a diesel fuel spray is described and discussed.