open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,everyone

When I use THOMPSON boundary condition, the result doesn't look good,although the

problem of "ill imposed free velocity" has been solved. There isn't any change of

tidal elevation in the whole domain at all(remains inial elevation).

Could anybody tell me about the reason?

Besides, I have some questions:
1)I set 3 open liquid boundaries in Matisse, why does telemac2d treat the

consecutive open boundaries as only 1 open boudary?

2)because of the question 1), when using THOMPSON boundary condition

the keyword should be "option for liquid boundary=2;2;2" or

"option for liquid boundary=2"

3)when using open boundary file or SL function(or BORD soubroutine), is it

necessary to give precribed value in the steering file?

4)In Bord subroutine, Can tTIDAL_MODEL_T2D be used to provide tidal elevation

boundary node by node? When does the subroute start running usually?

5)How can we set the starting time for tides simulation?

Sorry for asking so many questions, but they really bothered me a lot.

Any advice would be appreciated.

Hi
1) To have separate liquid boundaries, you should have solid boundaries between each liquid boundaries.
2) If you have 3 separate liquid boundaries, you should have option for liquid boundary=2;2;2 but if the 3 boundaries are contiguous, this is equivalent to only 1 boundary and the you could have only option for liquid boundary=2
3) Yes because some tests are made with this keyword
4)Tidal_model_2d was develop to provide tidal values at the boundary but with some other information (large model ...). You should check the documentation about those type of conditions because there is a lot of different options.
5) In telemac you have 2 keywords dealing with Date and Time taht allow you to specify the simulation date. Those keyword are used on large model if you activate TIDE GENERATING FORCE

Hope this helps

c.coulet,thanks a lot for your reply.

I'm still not quite clear about question (3)

Will the precribed value effect the results with open boundary file or SL function as well?

No
The valeu should exist as a default value but during the computation, this walue is replace by result of SL function or Value from open boundary file (the read call is made in SL)

Now I'm clear.

Thanks again.