Volume of fuel injected

[S. McManus]

Jason:

The volume (or mass) flow rate usually given is for an injector being held
open (static flow). For example, if you took an injector rated at 200cc/min=
, supplied
it with the recommended fuel pressure, and opened it for one minute, you
should have very close to 200cc of fuel on your floor. =20

What's probably more important though is dynamic flow. You should be able
to get a spec for the volume/mass for say a 2.5 ms pulse width.  This will
be quite different than what you would calculate from the static flow,
due mainly to the fact that the fuel has mass and therefore takes a finite
amount of time to accelerate to the static flow rate.
(theoretical calculation: [volume delivered(grams)]=3D[pw(seconds)]*[static
mass flow rate(grams/sec)])

On the other hand, if you truly had a 500 ms (1/2sec) second pw, dynamic
and static flows would be practically equal.

Sean McManus
University of Washington Mechanical Engineering
=20

On
Tue, 8 Oct 1996, Jason Walters wrote:

> I=92m most definitely not up to the level of expertise of this group, but
> I don=92t know where else to field my question.
>=20
> Here=92s my problem.  I=92m trying to calculate the volume per burst for =
a
> typical fuel injector.  I=92ve downloaded some specifications, but I=92m =
at
> a loss to break them down.
>=20
> If a given fuel injector has a flow off 150 cc/min, how many
> bursts/firings are we talking per 60 second interval?  Is that a
> measurement with the injector wide open for 60 seconds, or is that a
> measurement for something like 50 bursts with a duration of 15
> milliseconds per burst?  (I just pulled those numbers out of a hat)
>=20
> I need to be able to calculate the volume output of a 500 millisecond
> burst from say,  130, 150, and 200 cc/min fuel injectors.  The results
> don=92t have to be in metric (though I prefer them),  as I=92ve also come
> across measurements like 45 lbs/hour.
>=20
> Any help would much be appreciated
>=20
> Jason Walters
> jasonw at teleport.com
>=20