Mass burnt ECFM3Z problem

john_cu · September 17, 2019, 18:40

Hi,

i'm studying the combustion of a small diesel 2 stroke engine for APU usage , for my thesis project.
I'm using the ECFM3Z compression model, closed cycle, the engine is operating at 5000rpm, phi 0,75; I notice in spd01 that mass burnt starts to decrease in the end of combustion, when almost the fuel is burnt, and at the same time the fuel starts to increase, like there's new fuel in the chamber from nowere.

Actual time step is 0,2CA until the injection begins, then 0,1CA during injection/combustion,and again 0,2CA from 40CA ATDC to the end ( exhaust port opening).
Polymesh size is 1mm.
I tried to reduce mesh size, reduce the time step ( 0.05CA) and under relaxing pressure ( o,4) and additional scalars to 0,8 but the problem still remains.

What can i do?

alpie · October 22, 2019, 17:10

Have you already solved the issue you were facing here?

john_cu · October 22, 2019, 17:15

Quote:

Originally Posted by alpie

Have you already solved the issue you were facing here?

HI alpie, yes, I changed combustion model to ECFM CLEH

alpie · October 22, 2019, 17:20

Alright, thanks for replying. Most likely ECFM-3Z wasn't malfunctioning though. There must have been a setup error or inconsistency.

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October 22, 2019, 17:10		#2
alpie New Member Join Date: Oct 2019 Posts: 5 Rep Power: 7	Have you already solved the issue you were facing here?

October 22, 2019, 17:20		#4
alpie New Member Join Date: Oct 2019 Posts: 5 Rep Power: 7	Alright, thanks for replying. Most likely ECFM-3Z wasn't malfunctioning though. There must have been a setup error or inconsistency.