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-   -   Time step size with adaptive time steps (http://www.cfd-online.com/Forums/cfx/116091-time-step-size-adaptive-time-steps.html)

Racing_34 April 12, 2013 13:56

Time step size with adaptive time steps
 
Hi everyone,
i'm trying to run a transient simulation with adaptive time step length.
I have an expression in which i need the time step size, but i can't figure out how i can get that information. I tried both with dtstep and with "Time Step Size" but, even if in cfx-pre they're written in italic (which means i'm calling a built-in expression), in cfx-post i have this message "ERROR
The following unrecognized name was referenced: Time Step Size." and cfx can't calculate my expression.

So, how can i get the information i need?

Thank you

ghorrocks April 13, 2013 07:57

dtstep is available in the solver but not the post-processor. It should work fine in the solver. So I presume you are using it in the post processor. Why do you need it in the post processor?

Racing_34 April 14, 2013 10:15

Quote:

Originally Posted by ghorrocks (Post 420277)
dtstep is available in the solver but not the post-processor. It should work fine in the solver. So I presume you are using it in the post processor. Why do you need it in the post processor?

i'm modeling the saturation of a dual scale porous media, saturation is defined as 'accumulated saturation'+constant*t step size so i need to visualize it because it's one of my work's output

thanks

ghorrocks April 14, 2013 18:32

I cannot see a way of doing this in the post processor. You can do this in the solver by defining an additional variable and a source term. Alternately you can export the raw data and do the intgeration in another package (excel, matlab, python whatever you like).


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