User Forum of Software BASEMENT

Anto

User

Registered: 2016-03-23

Posts: 1

from 2D to 1D

Hello,

I’m working with 1D and 2D models. I have to carry out a hydraulic simulation on a very large area, so in order to optimize the computation time I need to use both 1D and 2D. When I use the coupling tool from 1D to 2D it works. But when I try from 2D to 1D BASEMENT fails. I need to create a simple coupling interface (sequential), water flows through the 2D output boundary and then enter into the 1D model. I have tried with several coupling types but it doesn't work (BASEMENT crashes or nothing flows through the 1D).
What could be the problem? 

With output boundary (2D)= “coupling_zero_gradient” and input boundary(1D) = “coupling hydrograph” BASEMENT crashes.

Any suggestions would be gratefully appreciated.

sajjad

User

Registered: 2014-10-01

Posts: 101

Re: from 2D to 1D

Hi,

I may add my experience as well, in which, I tried to build a coupled 1d-2d model but the simulation failed. The water would not enter the 2D (downstream) domain. I tried suggested remedies e,g, (a) refine the mesh at 1d-2d interface, (b) reduce the no. of nodes at the interface but none worked.

Thanks

Stephan Kammerer

Developer

Registered: 2015-03-31

Posts: 67

Re: from 2D to 1D

Dear users,

Here I provided an example of a coupled hydraulic simulation. Please have a look at the command file (run.bmc) in the input folder for the correct definition of the boundary conditions and coupling interfaces.

Regards
Stephan

sajjad

User

Registered: 2014-10-01

Posts: 101

Re: from 2D to 1D

Dear Stephan,

I have created my 1d-2d file minutely, based on your model. It still does not work. Please have a look at my files:

Link for 'Input' : https://drive.google.com/open?id=0B9Ci9 … XhrVFFGalU
Link for 'description' : https://drive.google.com/open?id=0B9Ci9 … FdPX2hyd0k

Would be so grateful, if u can take some time out to help

Thanks

Stephan Kammerer

Developer

Registered: 2015-03-31

Posts: 67

Re: from 2D to 1D

Hi Sajjad,

I took some time to take a look at your coupling model. From my perspective there was a problem with the resart files of the 1D subdomains, which led to a freeze of the GUI during the initialization of the model.  Here you can find the modified files I used to run the model. Furthermore I modified the command file (run.bmc) and added the tag "slope" for the upstream boundary conditions in the 1D domains "lowerchan" and "rightchan". The slope is needed to compute the second boundary condition due to supercritical flow conditions. Unfortunately there is no warning appearing in the GUI in case of missing tag "slope" for BOUNDARY type "coupling_hydrograph". We will add a warning for this case.
The model is running now, however there are still some adjustments necessary indicated by a large number of warnings. In general the model setup is quite ambitious as you have supercritical conditions with very low water depths in combination with 4 coupling interfaces.

I hope I could help you anyway,
Stephan

sajjad

User

Registered: 2014-10-01

Posts: 101

Re: from 2D to 1D

Dear Stephan,

very very kind of you to have given your time to see and correct the files.The problem, as before, is that the  flow does not enter the 2D domain from the leftchan and topchan. However, with corrected restart files, flow does enter the 1d domains 'topchan' and 'leftchan'. maybe I should try some less stringent coupling b. conds.

Thanks and regards