open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

I run the simulation for a Gulf region for a week. I got very odd results! but it was not the same when I ran the model for a day.

Please find the attachment for the simulation files and images of the results.


Thank you,
Sathish

Hello Sathish

Unfortunately, there is no attachment in your post. Please try again.
and meanwhile, you can give some additional details since your question is a bit vague.

with my best regards

Riadh ATA

Hello Riadh,

I ran the model for a day (time step=5sec) and the results are like 3-4m/s velocity with the default bottom friction condition.

I try to check the model stability so I did run the simulation for a week using the same condition but it gives me like 450m/s!. I checked the location of the peak values it comes from some of the offshore boundary nodes.

I attached but don't know what went wrong, so I emailed you the files

Thanks,
Sathish

Hello,

Most probably your offshore nodes have a prescribed elevation and a free velocity, with entering velocity, which is not a well posed problem. Did you try the Thompson's boundary conditions?

With best regards,

Jean-Michel Hervouet

Hello Hervouet,

I did try Thompson boundary conditions but it's not working in my case. I tried 5 4 4 and imposed boundary conditions, seems working but getting peak velocities (5m/s) values all along the Gulf shore.

Thanks,
Sathish

Hello,

Do you have velocity measurements? In this case you could try boundary conditions 5 6 6 so that the Thompson's boundary conditions work better with the velocities, otherwise information may be lacking when the velocity is entering the domain and this is why you get peak velocities.

With best regards,

Jean-Michel Hervouet

Hello JMH,

Velocity reading! well, I don't have much data. I have it for only two or three location. I guess it will be difficult to calibrate the whole domain with the data I have.

Between, I'm getting more than 15m/s while using Thompson(566) and 4-5m/s when I used imposed boundary condition (544)

Thanks,
Sathish

Hello Sathish

is it OK with 544 conditions?
I tried with your new model before leaving to my vacations and it seemed working better with 544.

What I suggest also to do is to remove the tide condition, just to test the stability of the model. you can start by prescribing a mean value of the elevation and see if the model will stay stable with reasonable results.

Kind regards from Marseille

Riadh