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Forrest October 22, 2003 05:43

Transient time information
Hi everyone! I tried to use both CFX4 and CFX5 to run a transient case. Animations (.mpeg files) can be produced using CFX5.6 post, wondering how to update the real time information automatically in terms of each image for each solution at the time. Thank you for your help. Regeards, Forrest

Glenn Horrocks October 22, 2003 18:25

Re: Transient time information
Hi Forrest,

I don't understand what you mean. Do you want to show the simulation time on the frames of the animation?


Forrest October 23, 2003 04:43

Re: Transient time information
Hi Glenn, Thank you for your quick reply and sorry for the confusion. Yes, I do want to show the simulation time (real time) on each frame. During the transient simulations I need to change the real time step since the flow was changing fast at the start, then getting slow. When I play the movie (mpeg file) made by CFX5.6 post, by standard, it's always 24 frames per second, so it doesn't make much sense about the real time although it is good enough to have an idea about the fluid flow. Thanks again, regards, Forrest

Glenn Horrocks October 23, 2003 18:28

Re: Transient time information
Hi Forrest,

I put the simulation time on an animation of a transient simulation by using a session file. After setting up the basic layout of the screen and the views, record a session file where you load the next timestep, update the timestep counter and print the screen as some sort of graphics format (bmp or png or whatever). You can then adapt the session file with perl script to increment through all your timesteps and update the timestep counter and save it as a numbered graphics file. You can then use MPEGencode (which comes with CFX) or imagemagick or whatever to create an animation.

I don't know of any way of doing this directly in CFX-Post. If I have missed something somebody please let me know - otherwise please take this as a feature request CFX/ANSYS.

By the way, as you probably know, the slowest frame speed which you can record an MPEG in CFX-Post is 24 frames per second. This is way too fast for most CFD animations and the entire simulation zips through in a second or so, and a frame rate of 3 to 6 frames per second is more reasonable. If you have created the image files as described above (or use the "Keep intermediate graphics file" option in CFX-Post) you can create an MPEG with a slower apparent frame rate by using MPEG encode yourself, and repeating frames. This way it is easy to make the frame rate 2,3,4 or 6 frames per second which is far more easily viewed. (If you could do this automatically in CFX-Post that would be great - take this as another feature request CFX/ANSYS!)

You can find MPEG encode (in windows) in CFX/CFX-5.6/tools/share/src/mpeg_tools/

Regards, Glenn

Forrest October 24, 2003 03:57

Re: Transient time information
Hi, Glenn

Thank you very much for your comments. They are very helpful. I am going to have a goal. Cheers, Forrest

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