Fuel Velocity
Turbo Mini Forums

Anyone have any idea of the velocity of the fuel leaving an injector nozzzle? Assuming normal 3 bar fuel pressure.

I've done my injection timing calcs on air velocity, but I'm pretty sure that the fuel travels faster than the air at light loads.

Edited by Paul S on 28th Feb, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I have no idea but I would assume that this will be very dependent on the injector type. The pencil-stream injectors you want to use probably have a much faster fuel velocity than ones with a very fine mist.

Jean

http://www.jbperf.com/

If I assume that the minimum velocity in the port is 5 m/s then I get the right sort of answers.

But the at the other end of the scale at WOT at 6000rpm, the air velocity is 40 m/s and it will take some time to accelerate the fuel.

Calculating the injection timing is far more complex than I originally thought.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

This may be of some use: In the ball park for typial low pressure PFI:

http://www.hull.ac.uk/php/331346/publicati...%20injector.pdf