Reading a variable at two different times instants using CFX expression

visitor · September 10, 2022, 07:29

What is the best way in performing such an activity?
Example;
Expression A reads CO at current time,
Probe(CO.Density)@Point 1

How can I read the above in expression B at for instance 1 or more time steps later? This will allow me to compare expression A v B. Thanks.

ghorrocks · September 10, 2022, 21:40

There is no fully supported way in CFX to do this. It is requested all the time.

But you have two unsupported methods to do it:
1) Write a user fortran routine to do it.
2) Using TRANS_LOOP - search for it in the CFX forum.

But don't forget unsupported means it might not work, it could give unexpected results and it could completely fail.

visitor · September 11, 2022, 07:05

Thanks ghorrocks, don't know fortran just C++. It's interesting that we are having these discussions and I hope CFX can do something about this through expression language.

Opaque · September 11, 2022, 12:35

Let us say, Ansys adds support for it w/o knowing your intended use and later you realized that was not enough. What then?

Perhaps if you share the intended use, someone in the forum could explain how to do it using existing features.

September 10, 2022, 07:29	Reading a variable at two different times instants using CFX expression	#1
visitor Senior Member AH Join Date: Apr 2014 Posts: 282 Rep Power: 13	What is the best way in performing such an activity? Example; Expression A reads CO at current time, Probe(CO.Density)@Point 1 How can I read the above in expression B at for instance 1 or more time steps later? This will allow me to compare expression A v B. Thanks.

September 10, 2022, 21:40		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,728 Rep Power: 143	There is no fully supported way in CFX to do this. It is requested all the time. But you have two unsupported methods to do it: 1) Write a user fortran routine to do it. 2) Using TRANS_LOOP - search for it in the CFX forum. But don't forget unsupported means it might not work, it could give unexpected results and it could completely fail. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

September 11, 2022, 12:35		#4
Opaque Senior Member Join Date: Jun 2009 Posts: 1,815 Rep Power: 32	Let us say, Ansys adds support for it w/o knowing your intended use and later you realized that was not enough. What then? Perhaps if you share the intended use, someone in the forum could explain how to do it using existing features. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Illegal cell label -1, fluent3DMeshToFoam	BenGher	OpenFOAM	7	October 10, 2023 00:02
How to define a static aditional variable in CFX	cardioCFD	CFX	8	January 22, 2018 04:58
Evaluating expression at a specific location in CFX Pre	gotang	CFX	4	August 17, 2017 10:33
Modify SST kw model in CFX	Tingyun YIN	CFX	6	May 12, 2017 06:44
CFX Expression Language help	JuPa	CFX	3	April 21, 2013 07:46

September 11, 2022, 07:05		#3
visitor Senior Member AH Join Date: Apr 2014 Posts: 282 Rep Power: 13	Thanks ghorrocks, don't know fortran just C++. It's interesting that we are having these discussions and I hope CFX can do something about this through expression language.