Instabilities Distant from Channel

[sloan1411 0]

Hello

 

I have created a modified version of an existing 1D Estry/2D Tuflow model. 1D consists of a main channel 1.8km and a 2D covers 1.2 long x 0.5km high (2.5m grid)

Instability problems occurs very early in the a 100yr run (generally 20mins). When I look at the error messages, the instabilities do not make sense.

 

For one thing, the instabilities are occuring well away from the flooding extents determined using previous simulations of the existing model. They are also located far away from the 1d channels and their boundaries (about 1.0km away). Attached in a image describes my problems further.

 

Regards,

sloan1411

 

Unstable.bmp

[par 0]

Hi Sloan,

 

The instability seems to be occuring near the edge of the model, is there a boundary out there?  Is anything in the _bcc_check.mif?  If you are not expecting to see water out there, i would suggest running the model with a frequent output interval, this should help determine where the water is coming from!

 

Regards

Phillip

[lei.yang 0]

in addition, we normally give the inflow to the 1D boundary. i notice that the red arrow was placed in 2D domain in your attached bmp which means that some inflow was provided to 2D. if so, the inflow could lead the water as the out-of-bank flow starting at beginning of your run to cause the instability.

 

hope helps.

 

regards

Lei