Ocean Modeling Discussion

ROMS/TOMS

Search for:
It is currently Mon Jul 15, 2019 8:27 pm




Post new topic Reply to topic  [ 4 posts ] 

All times are UTC

Author Message
 Post subject: Numerical error
PostPosted: Wed Sep 26, 2007 3:53 pm 
Offline

Joined: Wed Feb 28, 2007 8:00 pm
Posts: 23
Location: Massachusetts Institute of Technology
Hi All,
I consider a simple case of wind driven flow in the channel (Wall and periodic BCs) with sloping bottom (cross the channel). So there should be no variation in the flow along the channel. But the output of the run demonstrate significant variations in the flow along the channel.

I believe there is some kind of numerical error. I use domain depth x Ly(cross the channel) x Lx : 70-73m x 250m x 100m with number of points respectively 25 x 80 x 10.

The flow near the shallower part seams to demonstrate almost x-independent behavior and it is the deeper part that have strong along the channel variations. (Looks like it seats near the periodic boundaries occupying 2 grid points and then decreasing towards the area in the middle)

Could you give me any suggestions on this?

Thanks a lot,
Evgeny


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Sep 26, 2007 4:36 pm 
Offline
User avatar

Joined: Wed Jul 02, 2003 5:29 pm
Posts: 3633
Location: IMS/UAF, USA
It sounds a lot like the UPWELLING case which has been invariant along-channel when I've checked. Do you have more terms turned on than in UPWELLING? Is this serial or parallel? Is UPWELLING behaving for you? One thing to do to confirm your suspicions is to turn on the STATIONS option and put a line of stations across the periodic join. Then you can start playing games with turning off various terms until it behaves itself and you can tell us where the trouble lies.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Sep 26, 2007 4:57 pm 
Offline

Joined: Wed Dec 31, 2003 6:16 pm
Posts: 786
Location: USGS, USA
Evgeny-

I copied the setup files you sent and i see the disturbance that you are talking about. I changed
#define MIX_GEO_UV
to
#undef MIX_GEO_UV
#define MIX_S_UV

and it seems to work correctly now.
Give that a try and post a reply here.
This should allow you to continue while we dig deeper into mix_geo_uv.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Sep 27, 2007 8:11 pm 
Offline

Joined: Wed Feb 28, 2007 8:00 pm
Posts: 23
Location: Massachusetts Institute of Technology
Thanks a lot for the suggestions!

Now it does work when switched to
#define MIX_S_UV


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group