Time-averaged results for velocity at a specific plane via CFX

Shabi1992 · March 13, 2020, 02:26

Hello dear friends,

I am doing a transient simulation using CFX and my question is how can I get a time average flow field of simulation for a plane.
I tried to use the Arithmetic Average in CFX Output Control and it seems it just can be used for monitoring points?
Is there any way that we can get time-averaged velocity data on a plane?

Best Regards,

Gert-Jan · March 13, 2020, 05:17

I don't see the problem. If you create an Arithmetic Average on e.g. velocity in the Output Control of Pre, then in Post this variable should be available to plot on the plane and to do calculations with it. So, in Post you can determine the area average of the Arithmetic Average velocity using the calculator.

Shabi1992 · March 17, 2020, 21:16

Quote:

Originally Posted by Gert-Jan

I don't see the problem. If you create an Arithmetic Average on e.g. velocity in the Output Control of Pre, then in Post this variable should be available to plot on the plane and to do calculations with it. So, in Post you can determine the area average of the Arithmetic Average velocity using the calculator.

Many thanks for your reply.
Actually in output control, when I select the Arithmetic Average, I just can set the variable as eg. velocity. Is there any way that I also can define a plane to get such value on that?
If I use the areaAvg in Post, I just can get a number, however I need the time-averaged contour or .csv.
Thanks in advance

Gert-Jan · March 18, 2020, 02:44

You need to create an interface in your geometry and mesh it. Then, in Output Control, you can create a monitor for an expression like areaAve(Velocity)@interface. When you run it, you can create a monitor plot in the Solver manager. There, select that you want to plot the expression.
After the run, you can save the monitor data to a .csv-file.

Shabi1992 · March 18, 2020, 03:11

Quote:

Originally Posted by Gert-Jan

You need to create an interface in your geometry and mesh it. Then, in Output Control, you can create a monitor for an expression like areaAve(Velocity)@interface. When you run it, you can create a monitor plot in the Solver manager. There, select that you want to plot the expression.
After the run, you can save the monitor data to a .csv-file.

Many thanks for your kind reply.
But it seems based on your comment, I just can get the, for example, time-averaged of area-avg data on a plane?, however, I need the time-averaged data on that plane (for all elements) and then create a contour of that.
Is there any way that I can get the time-averaged data for the flow field for different coordinates?
Thanks again for spending your time,
Best Regards,

Gert-Jan · March 18, 2020, 03:47

I get lost completely. What you now ask is answered in my first comment. So again:

You can define time averaged variables in Pre. After the run, these are saved in the results files. Open the results file in Post, create a plane, select the transient averaged variable (click on the "...." button to look for it in the list) and there it is as a contour.

This is the average of the whole run. Unless you defined a time span in Pre. There you can select multiple time spans, like: 0-10s, 5-15s, 10-20s, etc.

Shabi1992 · March 18, 2020, 04:01

Quote:

Originally Posted by Gert-Jan

I get lost completely. What you now ask is answered in my first comment. So again:

You can define time averaged variables in Pre. After the run, these are saved in the results files. Open the results file in Post, create a plane, select the transient averaged variable (click on the "...." button to look for it in the list) and there it is as a contour.

This is the average of the whole run. Unless you defined a time span in Pre. There you can select multiple time spans, like: 0-10s, 5-15s, 10-20s, etc.

I see, Thank you so much for helping. I will try again and follow your instructions.

Shabi1992 · March 18, 2020, 05:36

Quote:

Originally Posted by Gert-Jan

I get lost completely. What you now ask is answered in my first comment. So again:

You can define time averaged variables in Pre. After the run, these are saved in the results files. Open the results file in Post, create a plane, select the transient averaged variable (click on the "...." button to look for it in the list) and there it is as a contour.

This is the average of the whole run. Unless you defined a time span in Pre. There you can select multiple time spans, like: 0-10s, 5-15s, 10-20s, etc.

I could get the time-averaged values and I really appreciate your help.
Best Regards

March 13, 2020, 02:26	Time-averaged results for velocity at a specific plane via CFX	#1
Shabi1992 New Member Join Date: Oct 2015 Posts: 28 Rep Power: 10	Hello dear friends, I am doing a transient simulation using CFX and my question is how can I get a time average flow field of simulation for a plane. I tried to use the Arithmetic Average in CFX Output Control and it seems it just can be used for monitoring points? Is there any way that we can get time-averaged velocity data on a plane? Best Regards,

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March 13, 2020, 05:17		#2
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,827 Rep Power: 27	I don't see the problem. If you create an Arithmetic Average on e.g. velocity in the Output Control of Pre, then in Post this variable should be available to plot on the plane and to do calculations with it. So, in Post you can determine the area average of the Arithmetic Average velocity using the calculator.

March 18, 2020, 02:44		#4
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,827 Rep Power: 27	You need to create an interface in your geometry and mesh it. Then, in Output Control, you can create a monitor for an expression like areaAve(Velocity)@interface. When you run it, you can create a monitor plot in the Solver manager. There, select that you want to plot the expression. After the run, you can save the monitor data to a .csv-file.

March 18, 2020, 03:47		#6
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,827 Rep Power: 27	I get lost completely. What you now ask is answered in my first comment. So again: You can define time averaged variables in Pre. After the run, these are saved in the results files. Open the results file in Post, create a plane, select the transient averaged variable (click on the "...." button to look for it in the list) and there it is as a contour. This is the average of the whole run. Unless you defined a time span in Pre. There you can select multiple time spans, like: 0-10s, 5-15s, 10-20s, etc.