Limiting k and epsilon

ksv · July 11, 2013, 05:04

Dear Foamers,
Kindly help me in limiting k & epsilon values. Am using LaunderSharmaKE model and want to limit the k and epsilon values within certain range. I tried something like below
k_ = min(k_, 5)
in LaunderSharmaKE.C file and compiled. But nothing works. Kindly correct me.
Thanks
KSV

Tobi · July 11, 2013, 06:42

I am not 100% sure but maybe you can use the following scheme:

Code:

div(phi, Epsilon) Gauss limitedLimitedLinear 0 5 1;

In which line did you insert your line?
And what is the reason for limiting your k - value?

ksv · July 11, 2013, 21:02

Hi Tobi,
Thanks your suggestion and will try it today. I inserted it below the solve(kEqn) line in the LaunderSharmaKE.C file. Honestly speaking I dont know as where to put it. The reason for limiting k values is that it is blowing up to huge values in my simulations.
Thanks
ksv

Tobi · July 13, 2013, 03:12

Hi,

if your values blow up ... then its possible that you have wrong BC or a bad mesh or anything is going wrong.

July 11, 2013, 05:04	Limiting k and epsilon	#1
ksv New Member ksv Join Date: Feb 2011 Posts: 16 Rep Power: 15	Dear Foamers, Kindly help me in limiting k & epsilon values. Am using LaunderSharmaKE model and want to limit the k and epsilon values within certain range. I tried something like below k_ = min(k_, 5) in LaunderSharmaKE.C file and compiled. But nothing works. Kindly correct me. Thanks KSV

July 11, 2013, 06:42		#2
Tobi Super Moderator Tobias Holzmann Join Date: Oct 2010 Location: Tussenhausen Posts: 2,708 Blog Entries: 6 Rep Power: 51	I am not 100% sure but maybe you can use the following scheme: Code: div(phi, Epsilon) Gauss limitedLimitedLinear 0 5 1; In which line did you insert your line? And what is the reason for limiting your k - value?

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July 11, 2013, 21:02		#3
ksv New Member ksv Join Date: Feb 2011 Posts: 16 Rep Power: 15	Hi Tobi, Thanks your suggestion and will try it today. I inserted it below the solve(kEqn) line in the LaunderSharmaKE.C file. Honestly speaking I dont know as where to put it. The reason for limiting k values is that it is blowing up to huge values in my simulations. Thanks ksv

July 13, 2013, 03:12		#4
Tobi Super Moderator Tobias Holzmann Join Date: Oct 2010 Location: Tussenhausen Posts: 2,708 Blog Entries: 6 Rep Power: 51	Hi, if your values blow up ... then its possible that you have wrong BC or a bad mesh or anything is going wrong.