"How do I generate ... 2 mg ..."

The answer is non-trivial, but different from what you may assume:

* (Assuming a CR injection system) the injection profile for your pilot injection is just the value of your existing profile - for the 2 mg set value.

* What you may have to newly calibrate is the profile for the main injection that may be affected by the pilot injection.

* Depending on the inter-injection pause (mainly variable vs. constant), you may even have to provide for a dynamic correction of the main injection.

For a system other than CR, the whole system will be even more complex ...

Hi Laurel,

I think your main question is how to obtain the injection rate profile from a single known injection rate by such as scaling method, right?

Since the injection rate profile depends on many factors, i.e. injection pressure, nozzle and sac geometries, and needle valve motion (lifting and wobbling), I am afraid you can't simply scale the main injection rate profile to get the pilot injection rate profile, especially when the injection duration is very short which results in transient injection.

Try to get that pilot injection profile by injection rate measurement device. :)

Best,

Radit

Hello,

One way to get the injection profile for different fuel flow rates is to check the manufacturer injector characteristics. Otherwise, a linear scaling of the profile would be a good estimate to preserve the required the fuel flow rate. The quasi 1-D fuel flow rate equation could be used to compute a new average for the injection profile and hence the scaling of the profile.

fuel mass flow rate=rho Integral of{ 2 pi r U(r) dr}