Changing an Option selection using CEL.

visitor · January 1, 2019, 06:59

Can anyone help please?
Looking for away to change an Option through CEL in CFX.
Example from
Option = Adiabatic
to
Option = Non Adiabatic
I do know the nested IF statement in creating an IF and ELSEIF conditions. However how do i create a switch between these options? Say example if the temperature =< 400 K, then Adiabatic elseif Non Adiabatic.

Thanks in advance.

ghorrocks · January 2, 2019, 06:22

Rather than switch between non-adiabatic and adiabatic conditions, why not just define it as a non-adiabatic condition (with a heat flux I presume), and then for the times it is adiabatic just define the heat flux to be zero. Then the if statement is a simple numerical one.

visitor · January 2, 2019, 07:42

Thanks for your reply.

Need to change automatically from within CEL. With an if condition statement. Have tried it, but didn't work.

Working on a student version, if it makes a difference.

ghorrocks · January 2, 2019, 23:18

Student version of CFX/ANSYS is the same as the full commercial version, just the number of nodes in the mesh is limited and not all the physics is available.

You cannot change the boundary condition type with a CEL if statement. When you change boundary condition type you need to run it through CFX-Pre again to update things, you cannot do it with a CCL update alone.

Your options are:
* Use the method I described in my previous post
* Stop the simulation, and restart using a new simulation with the boundary condition updated to the new type and use the old simulation as an initial condition.

That's about it. You cannot change boundary condition type inside a run and continue the run.

visitor · January 3, 2019, 09:54

Thanks for your reply Gohrrocks.

May be i will look into Fluent, just incase there is away.

Thanks

ghorrocks · January 4, 2019, 02:49

Why? Stopping and restarting is simple, easy and can be automated if necessary. Is that not acceptable?

visitor · January 4, 2019, 07:29

Yes definitely, can be done. Just was looking for an automated way. Something like what a UDF does in Fluent. Will explore a way with Fluent, so far found nothing in user manual.

Thanks.

Opaque · January 4, 2019, 12:29

This is supported as a multi-configuration setup.

First analysis uses adiabatic as the Option, and the second analysis uses Flux In as the option.

The switching between the options is automatically taken care of once the trigger (logical) is satisfied.

visitor · April 1, 2019, 07:34

Thanks for your replies.

Was hoping to automate this to get more control. I think even fluent won't make it with a udf.

Thanks again.

January 1, 2019, 06:59	Changing an Option selection using CEL.	#1
visitor Senior Member AH Join Date: Apr 2014 Posts: 287 Rep Power: 0	Can anyone help please? Looking for away to change an Option through CEL in CFX. Example from Option = Adiabatic to Option = Non Adiabatic I do know the nested IF statement in creating an IF and ELSEIF conditions. However how do i create a switch between these options? Say example if the temperature =< 400 K, then Adiabatic elseif Non Adiabatic. Thanks in advance.

January 2, 2019, 06:22		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Rather than switch between non-adiabatic and adiabatic conditions, why not just define it as a non-adiabatic condition (with a heat flux I presume), and then for the times it is adiabatic just define the heat flux to be zero. Then the if statement is a simple numerical one. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

January 2, 2019, 23:18		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Student version of CFX/ANSYS is the same as the full commercial version, just the number of nodes in the mesh is limited and not all the physics is available. You cannot change the boundary condition type with a CEL if statement. When you change boundary condition type you need to run it through CFX-Pre again to update things, you cannot do it with a CCL update alone. Your options are: * Use the method I described in my previous post * Stop the simulation, and restart using a new simulation with the boundary condition updated to the new type and use the old simulation as an initial condition. That's about it. You cannot change boundary condition type inside a run and continue the run. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

January 4, 2019, 02:49		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Why? Stopping and restarting is simple, easy and can be automated if necessary. Is that not acceptable? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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January 2, 2019, 07:42		#3
visitor Senior Member AH Join Date: Apr 2014 Posts: 287 Rep Power: 0	Thanks for your reply. Need to change automatically from within CEL. With an if condition statement. Have tried it, but didn't work. Working on a student version, if it makes a difference.

January 3, 2019, 09:54		#5
visitor Senior Member AH Join Date: Apr 2014 Posts: 287 Rep Power: 0	Thanks for your reply Gohrrocks. May be i will look into Fluent, just incase there is away. Thanks

January 4, 2019, 07:29		#7
visitor Senior Member AH Join Date: Apr 2014 Posts: 287 Rep Power: 0	Yes definitely, can be done. Just was looking for an automated way. Something like what a UDF does in Fluent. Will explore a way with Fluent, so far found nothing in user manual. Thanks.

January 4, 2019, 12:29		#8
Opaque Senior Member Join Date: Jun 2009 Posts: 1,880 Rep Power: 33	This is supported as a multi-configuration setup. First analysis uses adiabatic as the Option, and the second analysis uses Flux In as the option. The switching between the options is automatically taken care of once the trigger (logical) is satisfied.

April 1, 2019, 07:34		#9
visitor Senior Member AH Join Date: Apr 2014 Posts: 287 Rep Power: 0	Thanks for your replies. Was hoping to automate this to get more control. I think even fluent won't make it with a udf. Thanks again.