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Robbedoes

cycle instead of time based calculation

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I wish to simulate some cycle dependent combustion engine systematics.

 

Fuel accumulation in the intake ports to be specific.

How to set up the calculation to calculate per engine cycle instead of time based?

So that i can make the following calculation.

A_curr.cycle = A_prev.cycle + B - C

 

**

The intake port can be seen as a vessel/tank that accumulates fuel in a puddle (Wall Fuel). 

The fuel injector squirts an amount of fuel into the intake port.

A small amount of the squirt adheres to the port wall puddle. 

A small amount is sucked from the port wall puddle. (The sucked off amound it dependent on the puddle size)

 

The puddle size starts a "0" and enlarges every engine cycle untill an equilibrium state had is reached.

The puddle size is what i want to simulate. 

The puddle size is= Adhere to Wall Amount (portion of injected amount) + Sucked Of wall Amount (portion of puddle size of previous cycle wall fuel amound).

WF=WF+AWA-SOC

**

 

Accel enrichment3.vsm

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You would need to use a discrete feedback system to solve this problem.  In the model (below), your equation is implemented as;

WF = WF_PreviousValue + AWA – SOA

 

You need to specify the initial value of WF_PreviousValue on the first pass of the simulation.  I have used the variable WF_Initial_Value (below) for this , you will need to assign it a value. 

image.png.13231b89531d8f4bfe4762f1c39ebef4.png

Robbedoes likes this

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On 1/9/2019 at 6:13 PM, Ric said:

You would need to use a discrete feedback system to solve this problem.  In the model (below), your equation is implemented as;

WF = WF_PreviousValue + AWA – SOA

 

You need to specify the initial value of WF_PreviousValue on the first pass of the simulation.  I have used the variable WF_Initial_Value (below) for this , you will need to assign it a value. 

image.png.13231b89531d8f4bfe4762f1c39ebef4.png

 

Fantastic Ric, thanks for the feedback. i am going to try that. 

Edit* Tried it. it works perfect. Thanks again Ric.

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