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October 13, 2011, 05:21 

#41 
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Sorry Marjan, that's about the limit of my knowledge on the subject. Let us know if you find a solution!


March 15, 2012, 03:58 

#42  
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Quote:
Update Loop = TRANS_LOOP] added to additional variable commands?? need more explaintions please, ASAP 

April 5, 2012, 03:08 

#43 
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April 5, 2012, 08:51 

#44 
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Edmund Singer P.E.
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What do you want to know?


April 6, 2012, 01:27 
how I can add update loop into my AV?&How we apply derivative at B.Cs

#45  
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Hi singer 1812 Actually, I would like to apply derivative w. r. t. distance at my b.Cs for u, v,w,E, and K. So does I can apply that using your advices into this thread? if so, how we can handle this without using user fortran into CFX solver? Thanks in advance 

April 6, 2012, 09:11 

#46 
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Edmund Singer P.E.
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You are trying to get d/dx not d/dt?
You dont need this method (update loop) to do that, that data is in already in solution. 

April 8, 2012, 18:51 
yes as you said

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April 9, 2012, 00:13 
misunderstand me

#48  
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Actually U misunderstand me because you talked about d /dx,y,z into post stage but what I'm looking for is set d../dx, d../dy &d../dz=0 at the boundary consitions (outlets) into set up stage. any input can help Regards 

April 9, 2012, 08:57 

#49 
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Edmund Singer P.E.
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Dont need transloop. Just setup a CEL expression for the derivative and put it into the BC under flow direction.


April 9, 2012, 09:02 

#50 
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Ahh, I didnt read your message carefully enough. You need it on the outlet.
To what purpose are you forcing the derivatives on the outlet? 

April 9, 2012, 21:10 
my model

#51  
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Quote:
Any input can help. regards 

April 9, 2012, 21:17 
how I input my neumann BC through flow dirrection

#52  
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Regards 

April 10, 2012, 09:50 

#53 
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I dont understand why you are trying to force an outlet to have a certain gradient. Is this purely to match something in liturature?
The opening will only apply those conditions to the flow coming into the domain, not the flow leaving it. The conditions of the flow leaving the domain are a function of what takes place inside. If you need the gradient to be zero wrt the boundary, use a symmetry BC. If it is non zero, I think you will need to use User Fortran to enforce that. 

April 11, 2012, 22:20 

#54  
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If I required any further recomments I will reask you 

April 12, 2012, 04:19 

#55 
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This method is right, frist you must run the fortan in your computer.


July 14, 2014, 18:06 
TRANS_LOOP operations

#56 
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Hello,
I am tring to use the TRANS_LOOP operation to solve the following equation in a CFX Domain: XX=1(1/((1XXold)^a+B*exp(C/(D*T[K]))*F*n))^a I am doing the following steps: · Create an additional variable XX which is defined by the expression : XX value: 1(1/((1XXold)^a+B*exp(C/(D*T[K]))*F*n))^a The variable is function of temperature. · Create another additional variable XXold which defined by the expression: XXold value: ave(XXold)@domain+XX()@domain*Time Step Size. · Initially, I run a simulation with initial values in Additional Variable Models XX=0 and XXold=0. But when I set for each variable its CEL expression I am getting this following message: "Bad expression value 'XXold val' detected in parameter 'Additional Variable Value' in object '/FLOW:Flow Analysis 1/DOMAIN:domain/SOLID MODELS/ADDITIONAL VARIABLE:XXold'. CEL error: The following unrecognised name was referenced: XX." Is there anyone who can help me to overcome this problem please? Thank you in advance for your advices and suggestions 

July 15, 2014, 08:37 

#57 
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Hello,
I am tring to use the TRANS_LOOP operation to solve the following equation in a CFX Domain: XX=1(1/((1XXold)^a+B*exp(C/(D*T[K]))*F*n))^a I am doing the following steps: · Create an additional variable XX which is defined by the expression : XX value: 1(1/((1XXold)^a+B*exp(C/(D*T[K]))*F*n))^a The variable is function of temperature. · Create another additional variable XXold which defined by the expression: XXold value: ave(XXold)@domain+XX()@domain*Time Step Size. LIBRARY:· Initially, I run a simulation with initial values in Additional Variable Models XX=0 and XXold=0. But when I set for each variable its CEL expression I am getting this following message: "Bad expression value 'XXold val' detected in parameter 'Additional Variable Value' in object '/FLOW:Flow Analysis 1/DOMAIN:domain/SOLID MODELS/ADDITIONAL VARIABLE:XXold'. CEL error: The following unrecognised name was referenced: XX." Is there anyone who can help me to overcome this problem please? Thank you in advance for your advices and suggestions 

July 15, 2014, 17:48 

#58 
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Hi emotep, I could be wrong, but on first glance, you have ave(XXold) and XX().
I think the issue amy be here....... 

July 15, 2014, 21:17 

#59 
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what do you suggest me. I am not using a variable such MASSFLOW or velocity for the variable I want to calculate. It is in fact independent. To calculate this I have already set an additional variable and express a CEL.
Thank you for your answer 

July 16, 2014, 23:31 

#60 
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this is covered here: http://www.edr.no/blogg/ansys_blogge...rations_in_cfx


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