HEC-RAS 5.0.3 1D/2D

[Anonymous]

Hi,

I’m trying to simulate 1D/2D and I’ve had many problems, bus I don’t know why. I’m using v. 5.0.3 and I have follow this document “http://www.hec.usace.army.mil/misc/files/ras/Combined_1D_and_2D_Modeling_with_HEC-RAS.pdf”.
The message error is:

**** ERROR: Solution Solver Failed ****

Unstable for Initial Iteration at 02SEP2008 0006

***** Warning! Extrapolated above Cross Section Table at: *****
(The extrapolation may have been caused by model instability)

Urubici01 teste from R.S. 7181.094 to 6662.051
Urubici01 teste from R.S. 6326.739 to 3667.368
Urubici01 teste from R.S. 3310.332 to 1236.624
Urubici01 teste from R.S. 1079.714 to 619.4326
Urubici01 teste from R.S. 331.0952 to 10.95156

**** The Model Has One Or More Error(s) ****

Unsteady Flow Simulation Terminated

Can you help me? Do you have any document, step by step. I’am using lateral strucutures too.

Thanks.

[Chad Ballard]

There are too many things to really get a specific answer for a very broad question. What I have found useful with modeling is to start off simple then add complexity bit by bit. Then I can pinpoint what is causing the problems with my model. For example a final 1D/2D model with lateral structures I would create a 1D model of the area and then run at various flows and look at the results. Once I am content then I might add connections to the 2D areas defined and run that at a few different flow values to see how the model is responding. Then further add the lateral structures, etc. By stepping through the modeling process this way you can locate the problems at each step. I see a lot of modelers throw everything together then hit go then they have a hard time finding out where there exact problem is.

[HUGO FAGUNDES]

Thanks Chad.

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