An Experimental Study on Droplet Size Characteristics and Air Entrainment of Elliptic Sprays 982546

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. Differences of air entrainment between the elliptic and circular spray in a dimensionless distance range of 100 to 200 were not observed.