Hi, everyone.. I have a question about how to save some data (pressure, velocity, etc) in ascii after each iteration in transient condition.

For example, I wanna get static pressure data at the center line of pipe from every autosaved cas and dat file.

Can I get them automatically with some setting?

Thanks in advance

Dear Jay,

If I have understood your requirement correctly, this can be done using Solve-Animate function. Refer to this posting. http://www.cfd-online.com/Forum/fluent.cgi?read=19688

Hopefully it may serve the purpose.

Prasad

I really appreaciated it. Perfect !!!

Hey, Prasad.. I have one more question. I changed the setting as you recommended. After every iteration time step, however, the following warning generates. -------------------------------------------------- (ani-monitor-update 1 #t #t) Warning: surface-integrate: empty surface cx-solution-plot: No data points in range.() -------------------------------------------------- I have no idea what's going on. Do you have any idea about that? Thanks. Jay

Hi Jay,

Error message "no data points in this range" refers to the possible mismatch between Plot Direction and the surface selected.

Please check if "Plot Direction" and "X Axis Function" in XY Plot dialogue box is properly set. These are not difficult parameters to set. Still you may refer to 31.8.1 in User's Manual of Fluent 6.1 (Chapter - Reference Guide) for these settings.

Generally ensuring correct settings of these options, the same error, which I have encountered earlier, is addressed.

Prasad

Thanks, Prasad.

I think I did a right setting for the options you mentioned. I set the Plot direction with "x:1,y:0" and X axis function as "Direction vector". Is there any setting which I can play with? and can I select more than one surface? Thanks, Jay

Dear Jay,

To try to answer your first question I need to know a little more about the surface(s) you have created. For the example you'd mentioned in the earliest message "I wanna get static pressure data at the center line of pipe", if the axis of pipe lies along the centre line of pipe and the flow taking place in positive Z-direction, you have to have a line (a form of surfaces) created along Z-axis. Then you can select Plot Direction (X=0,Y=0,Z=1), X-axis function direction vector, and the line surface. Note that the Plot Direction and the line surface selected are complementory to each other. Alternately, you can use Curve Length as the X-axis function.

About your other question: Yes, you can select more than one surface.

Prasad

Hey, Prasad Thank you for your fast response. My case is 2-D axisymmetric prob. The center line of pipe is x-axis. I wanna get a series of x vs pressure (or velocity) after each time step. The surface and the direction is not perpendicular but parallel. Right now, I have no idea so I saved the x-position vs pressure plot after simulation using saved cas. and dat. files. It is really cumbersome. Thanks in advance. Have a great weekend.

Jay

Hi, Prasad.

This is Jay. Actually, I can plot x-position vs pressure using Plot>>xy Plot tap using cas. and dat. files. (Option settings -> Options Node values ON, position x-axis ON, Plot direction x:1, y:0, and X-axis function : Direction vector).

As far as I know, I made the same setting as above when I set the options under Animate>>Define.. tap.

Can you give another advice?

Thanks Jay

Jay, I am trying myself that thing. Will be back as soon as as I get the solution.

Prasad

Hi, Prasad.

I think I can get some xy-plot using "execute command" menu. Thanks a lot.

Jay

Dear Jay,

It looks ok. Hope that should have served your purpose.

When I tried using my own methodology, it turned out to be a fiasco. I got the similar error

Prasad

[freeday]

I am junior in fluent. But, I do project about sloshing tank. Postprocessing is very important for my project. I don't have much time. But want capture total pressure every member/wall in my case. Can I get the data automatically when iterate the program?
And I want writing process in XY plotting automatically every iteration or time step. Because in my case need a history in every second..
May I use the Execude Commands? How I write the command? Thank you very much.

[bmahnic]

Originally Posted by jay
;112709

Hey, Prasad.. I have one more question. I changed the setting as you recommended. After every iteration time step, however, the following warning generates. -------------------------------------------------- (ani-monitor-update 1 #t #t) Warning: surface-integrate: empty surface cx-solution-plot: No data points in range.() -------------------------------------------------- I have no idea what's going on. Do you have any idea about that? Thanks. Jay

Check the axes properties. Maybe you have defined certain range that does not let you to plot something that is outside that range.