Effects of Different Injector Hole Shapes on Diesel Sprays 920623

Twelve different hole shapes for diesel injector tips were characterized with DF-2 diesel fuel for spray cone angle over a range of injection pressures from 21 MPa (3 kpsi) to 69 MPa (10 kpsi). A baseline and two of the most radical designs were also tested for drop-size distribution and liquid volume fraction (liquid fuel-air ratio) over a range of pressures from 41 MPa (6 kpsi) to 103 MPa (15 kpsi). All hole shapes were circular in cross-section with minimum diameters of 0.4 mm (0.016 in.), and included converging and diverging hole shapes. Overall hole lengths were constant at 2.5 mm (0.098 in.), for an L/d of 6.2. However, the effective L/d may have been less for some of the convergent and divergent shapes. For the cone angle measurements, the injector was operated as a single hole injector spraying continuously into ambient temperature air at a pressure of 0.86 MPa (125 psia) at an air density of 9.7 kg/m3, or about one-half the density of a typical engine at injection conditions. The drop-size measurements were made with the injectors spraying into air at 0.55 MPa (80 psia) at an air density of 6.2 kg/m3. The results showed little effect of hole shape on the fully developed downstream spray cone angle or drop-size distribution. Injection pressure had little effect on the spray shape, while increasing injection pressure reduced drop sizes modestly.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Effect of DPF on Particulate Size Distribution Using an Electrical Low Pressure Impactor


View Details


Experiences from Nanoparticle Research on Four Gasoline Cars


View Details


Theoretical and Experimental Studies of Electrospray for IC Engine


View Details