I'm getting some CFL violations at high levels in the domain. Which filter is recommended to minimize these effects?
Thank You!
damping filters?
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- Posts: 1604
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Re: damping filters?
Try
damp_opt = 3
w_damping = 1
dampcoef = 0.2
If that doesn't help your time step is probably too large.
damp_opt = 3
w_damping = 1
dampcoef = 0.2
If that doesn't help your time step is probably too large.
Re: damping filters?
Thanks very much meteo! I hope you are well. I have also found that increasing the number of acoustic substeps helps in many instances (increasing TIME_STEP_SOUND = 4 to 8 or 16) - but making it too big slows down the calculations. So I wanted to try the filtering you and some others on this forum had mentioned.
There are filters for high latitudes, but I thought you guyz mentioned a top-of-atmosphere filter - I think my CFL violations occur at top levels. Do you see that often in fine-gridded nested domains? (1km or less)
Have a great weekend!
Patti
There are filters for high latitudes, but I thought you guyz mentioned a top-of-atmosphere filter - I think my CFL violations occur at top levels. Do you see that often in fine-gridded nested domains? (1km or less)
Have a great weekend!
Patti
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- Posts: 1604
- Joined: Wed Aug 19, 2009 10:05 am
Re: damping filters?
Yes I did have problems few levels under the top, and fixed that with values I given above.
Maybe I can be of better help if you copy/paste exact cfl violation messages from the log.
Maybe I can be of better help if you copy/paste exact cfl violation messages from the log.
Re: damping filters?
Thank you for the replies on damping. I am having high level CFL violations show up before a run crashes. I am trying your suggestions right now!meteoadriatic wrote:Yes I did have problems few levels under the top, and fixed that with values I given above.
Maybe I can be of better help if you copy/paste exact cfl violation messages from the log.
Thanks - Patricia
EDIT: That didn't help - trying to adjust to DAMPCOEF = 0.1