Diesel Injector Spray Technology

[Vaughn MacKenzie]

Here is an interesting article, sure wish I could read the whole thing. They experiment with injector hole shape, number and size. This is from two years ago, you wonder what sort of conclusions were drawn.



One other article I read discussed concerns with HPCR systems where fuel is put under so much pressure the droplets break the sound barrier in the cylinder which causes problems and reduces fuel mixing in the cylinder.



http://scitation.aip.org/getabs/ser...00125000002000427000001&idtype=cvips&gifs=yes



Anyone happen to be a member of this website?



Vaughn

 

[Vaughn MacKenzie]

Another related topic, Bosch's Next Generation common-rail injector. Note below where it says they are working on "variable nozzle geometry. " Interesting.



http://www.boschautoparts.co.uk/pcDies11.asp?c=2&d=1

 

[rbattelle]

Here's a good free article. Not common rail, but it gives a nice discussion of the principles upon which modern injection theory are built.



Ignition and Flame Development



-Ryan

 

[Cooker]

One other article I read discussed concerns with HPCR systems where fuel is put under so much pressure the droplets break the sound barrier in the cylinder which causes problems and reduces fuel mixing in the cylinder.

Maybe that is why the newest HPCR injectors went back to a 5 hole design? Would larger, denser droplets help cure this problem?

 

[nickleinonen]

Maybe that is why the newest HPCR injectors went back to a 5 hole design? Would larger, denser droplets help cure this problem?

i think they went to that style due to emissions. i remember reading here on the tdr, that the major change in the new 5 hole ones other than going to 5 from 8 holes, was the angle of the holes, they are very steeply angled into the recess on the piston to "chase" the piston down the bore [sorta paraphrasing what i am remembering]

 

[Vaughn MacKenzie]

One comment I saw was preventing fuel droplets from adjacent injector holes from colliding with each other, so maybe they dropped to 5 holes to prevent this.



Vaughn