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amin_u50 September 6, 2013 15:44

divergence calculation
hi dears...
I am simulating HCCI engine with AVL FIRE
in many time steps my calculation don't converge and go to next step.
in convergence criteria my max number iteration is 150.
my underrelaxation factor are:
turb kin=0.4
do you have any idea?
best regards.

kimmhw September 9, 2013 02:49


If you write correctly, the factors seem too big.
The factors is surely case dependent.
But I can say in principal.
- momentum: 0.4~0.6
- pressure: around 0.1
- TKE & TDR: around 0.3 (it is recommended to use the same values in two)
- energy: around 0.8

I hope this can help.

amin_u50 September 9, 2013 03:59

Hi kimwh
are you sure this factor use for HCCI simulation?? but i see this factors in the CI simulation in tutorial. I think this values has not problem for HCCI simulation
what is your idea?

kimmhw September 9, 2013 04:52

Hi amin,

I cannot say just in general because I don't have detail information.
In general, your values seem too high.. especially, pressure.

amin_u50 September 9, 2013 04:59

Hi kimhw
thnx a lot for saying your ideas to me...
you are the best my friends...
I examine this factors..
thnx kimhw


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