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Hi,

I'm trying to run a simulation around Gulf of Mexico, but I have a instability problem.
I used local tidal conditions that I extracted from OTPS software.
The boundary conditions that I set on the est boundary with Blue Kenue are "open boundary with prescribed UV and h" 566.

the problem is that:
The run stops after few time steps if I use VARIABLE TIME-STEP= NO, (I need to run with a fixed time step)
If I set VARIABLE TIME-STEP = YES the results that I get are not good because the velocity are unreasonably high. (look screen-shoot)

Also I can't get any results if I use EQUATIONS = 'SAINT-VENANT EF', because when I try to open the results with Blue Kenue appear warning message, and the velocity look like everywhere zero.



Before I tryed to run the same case but I used the Atlantic Ocean solution, and problem was approximately the same.
I also fixed the mesh how suggested to me in the forum.


I have tried many options but didn't manage to solve the problem.

Please, anybody can help me to figure out this problem?

Thanks so much,
Cristina

In attach:
case file
bottom.slf
wall.cli
tidal local model: h_tst UV_tst

Hi
you probably have a problem with you initial condition.
If the initial water level and the imposed level at the boundary condition are too different this will create inconsistencies and by consequence high velocities...
The fortran file is missing so we don't know what you entered as initial condition.
Regards

Hi,

thanks for your fast reply

I'm trying to attach bottom.slf, h and UV.tst files but maybe too big,

In attach the princi.f


Thanks

Cristina

We are assuming a mean sea level of (MSL) of zero - is this correct when using the OSTP data base to provide data at the tidal boundaries (with Thomson [characteristic] BCs)?

I would like explain better the problem that I got on the simulation that I'm trying to run on the Gulf of , and what exactly I done

TEST 1)

I started to run this simulation with this first mesh (look mesh1)
In this case I used Gulf of Mexico local tidal condition, I compared the free Surface that I got with TELEMAC in one point along the boundary (west, est and north boundary) (see graph) with the measure Value in the same points, and the trend is not reasonable, so there is a problem that comes from the tidal boundary.

TEST 2)
After I changed the mesh (look mesh2), I used the Atlantic Ocean tidal solution, and I got still instability problem (look screenshot3 Velocity_mesh2AtlanticSolution.png and V_mesh2_Atlantic.png).
In this case i got high velocity values on the est corner in the top of the mesh.

TEST 3)
In the end, I used still the mesh2 but i improved some transitions of mesh sizes in a few areas the mesh and I have recreated new tidal BC (local tidal conditions ) files using the OTPS software.
The boundary conditions that I set on the est boundary with Blue Kenue are "open boundary with prescribed UV and h" 566.
and How explain in the post above the probelm is that in the last 2 TESTS:

The run stops after few time steps if I use VARIABLE TIME-STEP= NO, (I need to run with a fixed time step)
If I set VARIABLE TIME-STEP = YES the results that I get are not good because the velocity are unreasonably high. (look screen-shoot VELOCITY_MESH3_localTidalSolutionsOTPS.png)
and I have still the instability problem



Because I used different meshes, and nothing's changed I think that the instability is caused by inappropriate tidal BCS.
does anyone has an idea on my problem?

Also in attach the bottom.slf