constants of eddy viscosity transport in CFX

Hamda · August 5, 2018, 14:41

Hi,
I want to specify the constants for EVT model but I don't know for example what is C1 in CFX? there are five constants; C1, C2, C3, A+,

but in CFX I couldn't find such constants. I read tutorial and found nothing about that and will really appreciate if somebody helps me on this issue.

Many thanks

ghorrocks · August 5, 2018, 19:15

Different researchers call the constants slightly different names at times. You are going to have to compare the CFX theory documentation with your reference to work out which constant is which between CFX and your reference.

Hamda · August 5, 2018, 22:43

Quote:

Originally Posted by ghorrocks

Different researchers call the constants slightly different names at times. You are going to have to compare the CFX theory documentation with your reference to work out which constant is which between CFX and your reference.

what about CFX? how it calls them? because in CFX I didn't find any C1, C2,....currently my problem is where are they in CFX? as shown in my pic, I selected EVT model but there is no options to enter C1,..
I checked CFX tutorial and didn't find any thing.

Thanks

ghorrocks · August 6, 2018, 06:57

Please read my post carefully. You appear to have misunderstood it.

"Different researchers call the constants slightly different names at times." means that CFX might be using different variable names for the constants.

"You are going to have to compare the CFX theory documentation with your reference to work out which constant is which between CFX and your reference." means look in the theory manual (not the tutorial manual) for how CFX defines the modelled equation. Then you match the variables from the CFX equation to the equation in your reference paper and work out what variable names CFX is using for the equivalent variables.

Hamda · August 6, 2018, 07:12

Yes I understood your post and I already looked at the theory manual in CFX sites and the equation are exactly like my reference paper's. It seems that in CFX, they are not exposed in the GUI and I have to adjust the CEL to define them into CFX.

ghorrocks · August 6, 2018, 07:21

In that case look in the RULES and VARIABLES files to see if they are present and how to specify them in CCL: https://sharcnet.ca/Software/Ansys/1.../i1302715.html

August 5, 2018, 19:15		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Different researchers call the constants slightly different names at times. You are going to have to compare the CFX theory documentation with your reference to work out which constant is which between CFX and your reference. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

August 6, 2018, 06:57		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Please read my post carefully. You appear to have misunderstood it. "Different researchers call the constants slightly different names at times." means that CFX might be using different variable names for the constants. "You are going to have to compare the CFX theory documentation with your reference to work out which constant is which between CFX and your reference." means look in the theory manual (not the tutorial manual) for how CFX defines the modelled equation. Then you match the variables from the CFX equation to the equation in your reference paper and work out what variable names CFX is using for the equivalent variables. Hamda likes this. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

August 6, 2018, 07:21		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	In that case look in the RULES and VARIABLES files to see if they are present and how to specify them in CCL: https://sharcnet.ca/Software/Ansys/1.../i1302715.html Hamda likes this. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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August 6, 2018, 07:12		#5
Hamda Member Hamda Join Date: Jul 2018 Posts: 80 Rep Power: 7	Yes I understood your post and I already looked at the theory manual in CFX sites and the equation are exactly like my reference paper's. It seems that in CFX, they are not exposed in the GUI and I have to adjust the CEL to define them into CFX.