----- Original Message -----

From: Ed Anderson

Sent: Wednesday, March 31, 2004 7:57 AM

To: Rotary motors in aircraft

Subject: [FlyRotary] One more question (Tracy, see comments inred)

 

 

 

Good explanation and I agree with everything except the part about RPM not being used by the EC2.  Engine speed is a primary input to the system, hence the term "speed - density system".  

 

Ok, if I understand you correctly, Tracy,  then RPM IS a  computational variable in determining fuel injector pulse duration and not just the "frequency of injection" factor.  Is RPM an adjustment for "Volumetric Efficiency" at different rpms or used for a different purpose??

 

Ed

 

Guess a little more detail is needed to explain this.  The EC2 re-computes the injection requirements in real time.  Just before the intake cycle starts, it computes the required fuel for this individual intake cycle.  You can't get any more closely tied to RPM than this.

 

The volumetric efficiency is very much affected by the design of the intake system.  Since there are no two alike out there (at this time), it is not possible to take VE into consideration as a function of RPM.  Detroit has it much easier in this respect because they can control every detail of the engine.

 

Tracy