Collecting many time-velocity data in FLUENT

DarrenC · March 7, 2011, 04:17

Hello there,

I have a simulation whereby Im trying to extract approximately 5000 velocity points at different location of the flow domain at different time steps.

I initially tried to define rakes and use surface monitors to display and write the velocities at each time step to a file. But this method only seems to average out the velocity over the points of the rake and display a single velocity at each time step.

Then I tried defining approximately 5000 individual points but the HPC ran out of memory!

Does anyone know how to solve this problem I have. I might be using define monitors wrongly but Ive experiemented with different settings and it hasnt worked.

Hope someone can help me out here

Cheers
Darren

Amir · March 7, 2011, 08:05

Hi Darren,
the other choice is using a UDF that execute every time step and write your desired data to a specified file with pre-defined precision.

xrs333 · March 7, 2011, 09:36

File −> Export −> During Calculation −> Solution Data…

DarrenC · March 7, 2011, 23:11

Hello xrs,

I have tried your method and it seems to be working in my PC. I define a plane and save the points in the plane in ascii format. However when I scripted the TUI to run the same case in my HPC, the drop down menu of transient-export dosent have the ascii format. My PC and HPC are running exactly the same version 12.1 however the HPC is running a UNIX copy.

Do you know what might be the problem?

Cheers
Darren

DarrenC · March 8, 2011, 02:12

I just realised that you cant export files in ASCII format if you are using a parallel version of FLUENT!!!. Surely such an easy task can be achieved without using a UDF?

March 7, 2011, 04:17	Collecting many time-velocity data in FLUENT	#1
DarrenC Member Join Date: Sep 2009 Posts: 69 Rep Power: 16	Hello there, I have a simulation whereby Im trying to extract approximately 5000 velocity points at different location of the flow domain at different time steps. I initially tried to define rakes and use surface monitors to display and write the velocities at each time step to a file. But this method only seems to average out the velocity over the points of the rake and display a single velocity at each time step. Then I tried defining approximately 5000 individual points but the HPC ran out of memory! Does anyone know how to solve this problem I have. I might be using define monitors wrongly but Ive experiemented with different settings and it hasnt worked. Hope someone can help me out here Cheers Darren

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March 7, 2011, 08:05		#2
Amir Senior Member Amir Join Date: May 2009 Location: Montreal, QC Posts: 735 Blog Entries: 1 Rep Power: 22	Hi Darren, the other choice is using a UDF that execute every time step and write your desired data to a specified file with pre-defined precision.

March 7, 2011, 09:36		#3
xrs333 Senior Member xrs333 Join Date: Aug 2010 Posts: 125 Rep Power: 16	File −> Export −> During Calculation −> Solution Data…

March 7, 2011, 23:11		#4
DarrenC Member Join Date: Sep 2009 Posts: 69 Rep Power: 16	Hello xrs, I have tried your method and it seems to be working in my PC. I define a plane and save the points in the plane in ascii format. However when I scripted the TUI to run the same case in my HPC, the drop down menu of transient-export dosent have the ascii format. My PC and HPC are running exactly the same version 12.1 however the HPC is running a UNIX copy. Do you know what might be the problem? Cheers Darren

March 8, 2011, 02:12		#5
DarrenC Member Join Date: Sep 2009 Posts: 69 Rep Power: 16	I just realised that you cant export files in ASCII format if you are using a parallel version of FLUENT!!!. Surely such an easy task can be achieved without using a UDF?