HEC RAS 1D-2D

[Anonymous]

Hi I am currently working on the 1D-2D model on Hec RAS. When the simulation ends, I have this error. Someone can help me ? However, I linked my 1D area to 2D with lateral structures

***** Warning! Extrapolated above Cross Section Table at: *****

TORRAS TORRAS from R.S. 1967.766 to 554.4768
TORRAS TORRAS from R.S. 171.1987 to 13.84495

The maximum xsec wsel error was 84.625
TORRAS TORRAS 1662.188 at 14MAY2018 00:21:32

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

Finished Unsteady Flow Simulation

Writing Results to DSS
Finished Writing Results to DSS

Reading Data for Post Process

Running Post Processor HEC-RAS 5.0.3 September 2016

Finished Post Processing

Computations Summary

Computation Task Time(hh:mm:ss)
Completing Geometry 1
Preprocessing Geometry(64) <1
Unsteady Flow Computations(64) 5:51
Writing to DSS(64) <1
Post-Processing(64) 2
Complete Process 5:57

[Anonymous]

Now i have this error :

***** Warning! Extrapolated above Cross Section Table at: *****

TORRAS TORRAS R.S. 1967.766
TORRAS TORRAS from R.S. 1861.708 to 1740.744
TORRAS TORRAS from R.S. 1687.615 to 1463.601
TORRAS TORRAS from R.S. 308.4406 to 13.84495

The maximum xsec wsel error was 17.848
TORRAS TORRAS 1635.161 at 14MAY2018 01:15:46

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

Finished Unsteady Flow Simulation

Writing Results to DSS
Finished Writing Results to DSS

Reading Data for Post Process

Running Post Processor HEC-RAS 5.0.3 September 2016

Finished Post Processing

Computations Summary

Computation Task Time(hh:mm:ss)
Completing Geometry 1
Preprocessing Geometry(64) <1
Unsteady Flow Computations(64) 2:03
Writing to DSS(64) <1
Post-Processing(64) 3
Complete Process 2:09

[cameron]

This basically means your model is going unstable or it means your 1D htab parameters need to be adjusted.

You may need to lower your timestep or turn on the 1D/2D iteration option.

[Anonymous]

Hello Cameron, I restarted my model this morning trying to adjust the option of iteration 1D / 2D on 20.
Even by modifying my Htab (copy invert) and trying to change my time step I still have the same error. An idea ?

***** Warning! Extrapolated above Cross Section Table at: *****

TORRAS TORRAS R.S. 1967.766
TORRAS TORRAS from R.S. 1861.708 to 1847.852
TORRAS TORRAS from R.S. 1740.744 to 1635.161
TORRAS TORRAS from R.S. 1608.497 to 1498.896
TORRAS TORRAS from R.S. 209.7826 to 13.84495

The maximum xsec wsel error was 6.153
TORRAS TORRAS 388.5036 at 14MAY2018 00:18:56

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

Finished Unsteady Flow Simulation

Writing Results to DSS
Finished Writing Results to DSS

Reading Data for Post Process

Running Post Processor HEC-RAS 5.0.3 September 2016

Finished Post Processing

Computations Summary

Computation Task Time(hh:mm:ss)
Completing Geometry 1
Preprocessing Geometry(64) <1
Unsteady Flow Computations(64) 2:17
Writing to DSS(64) <1
Post-Processing(64) 9
Complete Process 2:29

[Anonymous]

My 1D zone works fine, however, when I try to connect my 2D zone to my 1D zone with a side structure, the simulation contains errors … help?

[cameron]

what is your time step?

[Anonymous]

During my modeling I use the following parameters :

Starting date : 14 MAY 2018
Starting time : 0000
Ending date : 14 MAY 2018
Ending time : 0300
Computation Interval : 2 seconds
Mapping Output Interval : 1 minute
Hydrograph Output Interval : 6 minutes
Detailed Output Interval : 6 minutes

Options and Tolerances :
Maximum iterations between 1D and 2D : 1
Water surface tolerance (m) : 0.01
Flow tolerance (%) : 0.1
Minimum flow tolerance (m3/s) : 0.003

Thanks for your reply !

[cameron]

set the max 1D/2D iterations to 20.

What is the weir coefficient you are using for the lateral structure? Did you try setting it to use 2D equation instead of weir?

This all only applies if the issues are near the 1D/2D connection.

[Antoine]

For now I use this coefficient for the lateral structure: 0.8
I tried using 1.1 and it works, I have no error stream
But I still have the same error and I don’t know how it can be solved

***** Warning! Extrapolated above Cross Section Table at: *****

TORRAS TORRAS from R.S. 1967.766 to 1847.852
TORRAS TORRAS R.S. 1740.744
TORRAS TORRAS R.S. 1687.615
TORRAS TORRAS R.S. 1641.775
TORRAS TORRAS R.S. 1608.497
TORRAS TORRAS R.S. 139.8516
TORRAS TORRAS from R.S. 101.1404 to 13.84495

The maximum xsec wsel error was 4.354
TORRAS TORRAS 56.40127 at 14MAY2018 02:38:18

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

Finished Unsteady Flow Simulation

Writing Results to DSS
Finished Writing Results to DSS

Reading Data for Post Process

Running Post Processor HEC-RAS 5.0.3 September 2016

Finished Post Processing

Computations Summary

Computation Task Time(hh:mm:ss)
Completing Geometry <1
Preprocessing Geometry(64) <1
Unsteady Flow Computations(64) 29
Writing to DSS(64) <1
Post-Processing(64) 2
Complete Process 35

[Anonymous]

I have built a combined 1D 2D model of a single stretch of river but by combining channela and terrain data for 2D area creation. But, the flow occurs in places beyond the 2D boundary area. Can anyone tell me the reason? thanks in advance.

[Author]

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