Calculating injection quantity

Hello.

I need a formula to calculate the quantity of fuel are forced through a nozzle at certain time on a certain pressure.

I have Bump quantity per injection.
0.20ml

injector pressure.
250 bar.

injecting time.
1 milisecond.


why i need it?
I want to find optimal nozzel ends for my engine.

Why not just tell us what your power goals and turbo choice are and I'm sure someone will know what nozzles would be appropriate

Problem is that it is not a wag engine.
It is russian tractor engine Д-65

To calculate the right fuel quantity I have to consider diesel viscosity and density.
Or only viscosity?
Definitely I have to consider nozzle hole geometry.

There is no way to accurately calculate what you want. You would need to develop a pump curve from empirical data. In other words just measure it.

much easier to just find a flow bench and measure it. Then you can derive a curve fit equation as an approximation, or several curves and do a rough interpolation between them. But be aware the relationship is not linear, and the ratios change with pressure not just hole size. So if you are using a cam-based pump like a VE pump from an ALH or a PD or a P-pump the flow rate changes with rpm.

Might be a good subject for a masters thesis but why not just measure it.

I use in-line 4 pump.
The pump is measured and adjusted at full throttle 0.2 ml per injection.
(Pump is capable only 400bar pressure.)
I use engine only in full throttle under load.
does not injectors are measured flow per minute (cc/min)?

WarmStart said:

Hello.

I need a formula to calculate the quantity of fuel are forced through a nozzle at certain time on a certain pressure.

I have Bump quantity per injection.
0.20ml

injector pressure.
250 bar.

injecting time.
1 milisecond.


why i need it?
I want to find optimal nozzel ends for my engine.

Click to expand...

Two methods of measuring flow: Raw and installed method.

Raw uses the nozzles physical characteristics when mounted to a test apparatus to generate a raw flow analysis using an ISO 4113 fluid at specific pressures and temperatures. This measures the constant flow volume and can be used to determine cavitation effects of the nozzle with the needle at maximum Min, Mid and Maximum lift.

Installed volumes generally use 5 pressure ranges of the pump system employed. Different pumps have different pressure/volume flow curves irrespective of the nozzle installed. Injector duration is a function of pump output in applications not employing CR or PD control systems. Having a separate model to control injector duration while maintaining a precise constant pressure and temperature is mandatory to generate any meaningful data.

You mention 250 bar, but the problem is and you don't seem to realize this is that the injection pump does not operate using a constant pressure. The pressure generated by the pump may be as low as 300-350 bar at idle (despite your injector being stamped 250bar) rising to over 1000 bar or more at full load.

The constant variation of pressure makes it all but impossible to use the pump on the engine to generate flow data, again pressure must be regulated to ultra precise standards to eliminate volume variations.

For the most part raw flow data can be used to determine your original applications flow range. This can be used to extrapolate a rough estimate for desired performance goals for any particular application.

I found what I was looking for in "Green Diesel Engines: Biodiesel Usage in Diesel Engines"

opening pressure is not injection pressure
injection pressure varies so wildly that you're better off driving the pump at the various speeds of the map, then powering the QA with a function generator to X voltage for a calculated 1000 strokes or whatever, have the injectors dumping into graduated cylinders.

Then you can populate your pump voltage map with actual numbers.