open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,
I am modelling a steady flow on a real river. The simulation runs successfully but the computed water level seems unreasonable in which the water surface was abrupt. I also noticed that the water level for each cross-sections was computed stably at the second time step (30 second) and without any change at the rest of the time steps. I am sure we can not get a stable results within 60 second.
I am confused with the results. So I used the same cross-sectional data and boundary conditions to model this river using HEC-RAS software. As a result, a more smooth water surface was obtained.
I am glad if anyone can help me. Thanks.

Hi
The attached file cannot be opened so hard do check your model, particularly about the unreasonable water level...
Nevertheless, If you run steady kernel, there is no reference to time so the first result which correspond to state 1 is right. The following results are the same is the boundary condition don't change that's logical...
Regards

Thanks for your reply. It helps me better understand the software.

I attached the result of water surface from steady kernel. The water surface is not smooth. Does it because of the geometry of the river?



Furthermore, I used the result as initial condition of unsteady modelling. The Mascaret told me that Open boundary 1 is with a supercritical flow. So the supercritical kernel was applied to run. However, an error was threw and I don't know how to fix it.



The masc files of steady and unsteady model were uploaded.



Thanks.

Hi
Not sure about the result as you doesn't show the hydraulic results tab but the longitudinal profile...
Impossible to open your tar file so try to use another zip format and upload your model again
Regards

Hi, coulet. Thanks for your reply.
The masc files have been uploaded with zip format.

Hi
You should define a mesh size otherwise you will never have good results.
You only use the given profile for the moment but the length is too huge.
You could try with 100m and adapt according to results

Regards

Thank your coulet. The model is run successfully when the mesh size of 100 m was adopted. A smaller mesh size of 50 m was also adopted but failed to run as shown bellow. So my question is whether there is a principle to define the mesh size ?



Moreover, I applied the results of steady flow 1850 m3/s as the initial condition of unsteady flow using supercritical kernel.



The unsteady flow runs successfully and simulated water level seems OK. However, the depth of outlet (cross section 11) is constantly zero at any time steps. I don't know how to fix it. The updated masc file for unsteady modelling is attached. The updated masc file of unsteady modelling is attached.






Thanks.