[TUD_FT]

Hi,

i want to use the acoustic Courant Number for transient simulations, becuase i invastigate the sound propagation in pipes. I use the option adaptive time step with Max. Courant Number, but Ansys CFX uses the "normal Courant Number".

I read in the Ansys CFX Theory Guide, that it is also possible to use the acoustic Courant Number (1.1.3.15, page 22):

"The timestep may be chosen adaptively based on a Courant number condition (for example, to reach
RMS or Courant number of 5). The acoustic Courant number is used for compressible flow calculations
having the expert parameter setting ‘compressible timestepping = t’."

Unfortunaly, i can't find this option in the expert parameters.

Can anyone please help me? Or does anysone know how to use the acoustic Courant Number in transient simulations?

Greetings

[ghorrocks]

That expert parameter might not be in the GUI but you can set it using the command interface.

[TUD_FT]

Thank you! I never worked with the command interface before. How can i adress this parameter?



Is there any good Tutorial or something else which explains the use of the command interface?

[ghorrocks]

The easiest way is to:
* Insert an expert parameter (any expert parameter, it does not matter which) using the GUI
* Right click on the expert parameter and select Edit in Command Editor
* Replace the expert parameter you just generated with the one you want to add.
* Click Process for it to process it and add it to the simulation.

[TUD_FT]

Thanks, it works!