Delphi Multec 3.5 - Page 68

Product Description Multec 3.5 Fuel Injector Application Manual
3-24 Delphi Energy and Chassis Systems
Revision: 11/05-1
Surface
Volume
DN
DN
D
ii
ii
*6
2
3
32
==
∑
∑
DV
90
describes the droplet size which 90% of the spray volume is smaller
than. This parameter is useful in understanding the overall droplet size
distribution spread.
Spray atomization measurements at Delphi are typically performed with a
Laser Diffraction instrument. The beam is located 100 mm from the
injector tip which is actuated at pulse width to deliver 15 mg/pulse of N-
Heptane.
Injector spray atomization is influenced by the following design
parameters:
• Cone angle (wider cones tend to have better atomization.)
• Flow rate (higher flows tend to have larger droplets.)
• Director design (atomization can improve with the number of holes.)
• Valve design (flow upstream of the injector affects atomization.)
• Fuel pressure (higher fuel pressure provides better atomization)