The Effect of Split Injection on Fuel Distribution in an Engine-Fed Combustion Chamber 930864
This research focused on the effects of split injection on fuel spray behavior in a diesel environment. It was done in a special designed engine-fed combustion chamber (swirl ratio of 5) with full field optical access through a quartz window. The simulated engine combustion chamber used a special backwards spraying injector (105°).
The electronically controlled injector could control the size and position of it's two injections. Both injections were through the same nozzle and it produced very rapid injections (1.5 ms) with a maximum injection pressure of 130 MPa.
Experimental data included: rate of injection, injector pressure, spray plume images, tip penetration, liquid and vapor fuel distributions, combustion pressure, and rate of pressure rise.
From 105° forward scatter images, tip penetration was observed to be very rapid and reached a plateau at 25 mm. Exciplex images indicated that fuel vapor reached the outer regions of the combustion chamber beyond the liquid limits and the liquid droplets vaporized quickly and uniformly throughout the spray plume.
These experiments indicate that a split injection changes the injection's mixing, vaporization, and fuel distribution, and that different injections can produce similar rates of pressure rise during combustion.