Use CEL in a transient analysis to record WSS at a specific time interval

Pezzzz · February 24, 2014, 16:42

Hi,

I running a simulation in Workbench to run a mesh independence study. I am using parametrisation and want to look at the effects of mesh on WSS at a specific point.

I know how to export the value from CFX post into the parameter set in CEL:
maxVal(wall shear)@Aneurysm

However as the simulation is transient, I would like to export the value at a specific time (0.64902s, #60).

I'm sure there is a simple function I am looking for, but I am not familiar with CEL. Any help is much appreciated.

Thanks

ghorrocks · February 24, 2014, 17:14

I have not done something like you request - but if you set the transient simulation up to finish at 0.64902s does the CEL function return the appropriate value?

Lance · February 25, 2014, 03:29

Wouldnt maxVal be a bad choice for a mesh independence study, since the location of the maximum value might change when you refine the mesh? Why not use a bunch of monitors with fixed locations instead? In that way you will get the value at any time during the solution.

mvoss · February 25, 2014, 07:34

If the point of interest is known on beforehand you can use the CEL probe-function most similar to your expression and hook it up to the parameters in wb.2.0.

Just an idea: you can use a step-function in combination with the count-function to check if the WSS in a certain range changes by refining the mesh somewhere. Like said above - just to check for the maxVal isn't what you are actually looking for.

Pezzzz · February 25, 2014, 16:56

@ghorrocks, Thats I good idea, I will give this a go, don't see why it would'nt work.

@Lance, You make a good point. Is there any chance you can give me some advice, on how to find the WSS values at specific points in the mesh? Or point me to somewhere that explains how to? As I said before I have little experience of CEL.

Thanks

Pezzzz · February 25, 2014, 17:19

I have looked at probe and the format is probe(<val|expression>)@<location>.

I assume the way to reference specific points as locations is to make source points for the <location> in CFX-Pre?

mvoss · February 26, 2014, 05:33

You create the location in cfx post by selecting a node number or a xyz-coordinate. If you want to monitor it during solving then you have to create a monitor point in cfx pre.

February 24, 2014, 16:42	Use CEL in a transient analysis to record WSS at a specific time interval	#1
Pezzzz New Member Josh Join Date: Nov 2013 Posts: 5 Rep Power: 13	Hi, I running a simulation in Workbench to run a mesh independence study. I am using parametrisation and want to look at the effects of mesh on WSS at a specific point. I know how to export the value from CFX post into the parameter set in CEL: maxVal(wall shear)@Aneurysm However as the simulation is transient, I would like to export the value at a specific time (0.64902s, #60). I'm sure there is a simple function I am looking for, but I am not familiar with CEL. Any help is much appreciated. Thanks

February 25, 2014, 16:56		#5
Pezzzz New Member Josh Join Date: Nov 2013 Posts: 5 Rep Power: 13	@ghorrocks, Thats I good idea, I will give this a go, don't see why it would'nt work. @Lance, You make a good point. Is there any chance you can give me some advice, on how to find the WSS values at specific points in the mesh? Or point me to somewhere that explains how to? As I said before I have little experience of CEL. Thanks Last edited by Pezzzz; February 25, 2014 at 17:13. Reason: inncorrect names

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February 24, 2014, 17:14		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	I have not done something like you request - but if you set the transient simulation up to finish at 0.64902s does the CEL function return the appropriate value?

February 25, 2014, 03:29		#3
Lance Senior Member Lance Join Date: Mar 2009 Posts: 669 Rep Power: 22	Wouldnt maxVal be a bad choice for a mesh independence study, since the location of the maximum value might change when you refine the mesh? Why not use a bunch of monitors with fixed locations instead? In that way you will get the value at any time during the solution.

February 25, 2014, 07:34		#4
mvoss Senior Member Matthias Voß Join Date: Mar 2009 Location: Berlin, Germany Posts: 449 Rep Power: 20	If the point of interest is known on beforehand you can use the CEL probe-function most similar to your expression and hook it up to the parameters in wb.2.0. Just an idea: you can use a step-function in combination with the count-function to check if the WSS in a certain range changes by refining the mesh somewhere. Like said above - just to check for the maxVal isn't what you are actually looking for.

February 25, 2014, 17:19		#6
Pezzzz New Member Josh Join Date: Nov 2013 Posts: 5 Rep Power: 13	I have looked at probe and the format is probe(<val\|expression>)@<location>. I assume the way to reference specific points as locations is to make source points for the <location> in CFX-Pre?

February 26, 2014, 05:33		#7
mvoss Senior Member Matthias Voß Join Date: Mar 2009 Location: Berlin, Germany Posts: 449 Rep Power: 20	You create the location in cfx post by selecting a node number or a xyz-coordinate. If you want to monitor it during solving then you have to create a monitor point in cfx pre.