抄録
An experimental study was performed in order to investigate the effects of eccentric location of needle inside a VCO diesel nozzle on internal cavitating flow and primary atomization, so the 10 times large-scaled VCO nozzle with two nozzle holes was employed. The needle was manipulated by a three-dimensional traverse with micrometers. Discussion in this study focuses on the behavior observed at a relatively low needle lift in three cases: 1st case where the needle is perpendicularly positioned from the center of the nozzle, 2nd case where the needle is perpendicularly positioned from locations with slight displacements from the nozzle center close to the nozzle hole, and 3rd case where the needle is perpendicularly positioned from locations with slight displacements opposed to the 2nd case. Differences of spray cone angle and discharge coefficient were hardly apparent between the 1st case and 3rd case. However large difference of spray cone angle was observed between the 1st case and 2nd case when the needle is positioned far from the common plane of the two holes axes. Trend and value of discharge coefficient in 2nd case were different from those in 1st case.
