2D Solution went unstable

[Anonymous]

I develop 1D model with daily boundary condition, the cross-section connect to storage area. model run completed from dry to wet season.

After 1D model run completed, I converted storage to 2D area, the model can run in dry season but crash in wet season (peal flow). I try to reduce weir coefficient to 0.1-0.2, turn on 1d/2d iteration to 20 and turn on Adjust time step based on Courant. I reduced running time step to 1 minute and 30sec, it still crash after run 48 minute.

it reported:

06AUG2011 05:46:45 SA SA-XBF3La 154.50 0.00
06AUG2011 05:47:41 SA 229 142.88 0.00
06AUG2011 05:48:25 SA 226 141.56 0.00

2D Solution went unstable

At time: 06AUG2011 05:48:31

2D Solution went unstable

2D Solution went unstable

2D Solution went unstable
At time: 06AUG2011 05:48:3
At time: 06AUG2011 05:48:
FO FONT= BLUE
At time: 06A At time: 06AUG2011 05:48:31

[cameron]

what is your cell size? What is the minimum flow? Are you using full momentum or diffusion wave for the solver?

[Anonymous]

cell size is 100 x 100 m. Model consists of main river and its tributaries, minimum flow is 10 m3/s for main and less than 1 m3/s for tributaries. I used diffusion wave.

Modeling contain Flow hydrograph and lateral flow.

Thank you very much.

[Anonymous]

Dear Cameron, do you have any suggestion on my problem?

[cameron]

Have you tried using the 2D equation instead of the weir equation for the lateral structure?

[ckatsoulas]

How wide is the river?, 100m cells seems way too big and you may need to introduce breaklines along the banks to align the cells along the river edges.

[Anonymous]

Yes, I did. Due to there are many lateral structures so I changed some.

[Anonymous]

Dear ckatsoulas,

river wide is rang from 150-200m. I did the breaklines to made 50m wide along the river. Due to a large area so the cell size was design for 100m. There are around 50,000 cell (100m*100m).

[Author]

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