open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi everyone,

I'm very new to TELEMAC2D and I'm trying to set up a simulation for a couple of islands. I think something is wrong with my boundaries conditions but I can't quite get what it is.

I have attached my model. It's a very simple one. The yellow lines are liquids, the purple line is my input. I want to use prescribed velocity as input.
Here are my questions:

1. what should be the boundary condition for the parts where there is nothing but water?
2. what should be the boundary condition for the water/land part?

I have tried liquid with prescribed elevation but my results don't make any sense. I have attached my cas file as well.

Any help would be much appreciated. Do not hesitate to point at all the wrong things I might be doing or give suggestions on how to complete a good simulations.

Thanks

Hi
For boundary condition where there is water, you should use one of the liqui boundary type, depending what you want to impose...
For interface between water/land this should stay as solid boundary.

I saw the yellow line on your attachment but no purple one...

If you're a newbie, start by looking the different exemple which are part of the system to well understand how telemac works.

Regards

Thank you for such a fast reply.

The purple boundary is the south side of my model. I mistakenly sent an old version. Sorry.

My main problem is I don't know what BC to impose on the boundaries. I have read a lot of posts in this forum, ran some simulations I found on it, read the manual, and went through the dico file. Unfortunately, I couldn't find the setup used when dealing with islands.

I used prescribed elevation for every boundary except the input side where I used prescribed flowrate.
I will try solid boundaries for water/land. Should I also make the boundaries of the islands solid?

If the island are not submerged, is it better to consider them as a real island in the mesh (not only in the bathymetry)

For the boundary condition, it depends on the reality...
Why prescribing elevation on some boundary and flowrate one the input side as the liquid boundary is continuous...
It seems your on a coastal area so the liquid bounadry should be a tidal one. This mean a least a prescribed elevation everywhere and better elevation and velocity.
There is a lot of automatic functionnlities for automatic management of tide in Telemac

regards

I will redo the mesh and cut the islands from it first.

There is little known about the real conditions of water flow in that area and the science paper I read about this gave one main assumption: water flows in the directions of the island (as in picture). The water is assumed to flow uniformly.

Where would you suggest the source be?
Based on your suggestions, I will try using red for liquid inflow velocity, black liquid for outflow velocity (see image).

I didn't quite understand this part from your reply: "This mean a least a prescribed elevation everywhere and better elevation and velocity."

Where is the site you're studying?

Taiwan - South East side
I'm simulating the flow next to the two islands right next to Taiwan.

Use TPXO database, this will simplify your problem as the boundary condition will be automatically managed...
Look TPXO exemple to configure your computation

Oh My Goodness!
I came across TPXO database and saw a few examples on it but had no idea it handled boundaries conditions.
I'm going to try that right now!! I will update this post on the outcome.
Thank you Thank you

Hello C.Coulet,

I tried using TPXO as you have suggested and found an example on this forum (the only example I could find). The example still has a boundary conditions file in it.
I tried running without a BC file, but it fails as well. Do you happen to have an example of how I could set my file up as you have suggested? This is the error I get.

Thank you for your help.