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Dear Users,

I have problem with tidal apmlitude in case of tidal simulation in North Sea Region. As a tidal database I use TPXO files. I have seen the post where it is said that for TPXO the Harmonic Constant File is not nessesary, but only Binary Database 1 and 2. With and without Harmonic constant files I have same results, very low amplitude, but Prdicted TPXO data shows high tide for same period. For example at one point I have 0, but TPXO predicts 3m. Only one area produces good results. It could be an open boundary problem, as results are wrong at boundaries except one area. I am not sure what else I can specify for boundary conditions. I have CONSTANT ELEVATION, and 566 and 4 in Boundary Condition File.
I thought it could be TELEMAC3D problem but when I run this case in TELEMAC2D I got same results. I attached the steering file, maybe you can spot some errors that cause such a low amplitude. Velocities are in normal range. In order to change the amplitude I have tried various Frictions Laws and Coefficients but it did not help. Please advise. Thanks a mil.

Kind Regards!

Violeta

Hi,

There is an option, COEFFICIENT TO CALIBRATE TIDAL RANGE, have you tried running the simulation by giving some value to it, try to give some higher value such as COEFFICIENT TO CALIBRATE TIDAL RANGE = 2.

With Best Regards,
Gourish

Hi Gourish,

Thank you very much for your reply. I was not sure if by using that coefficient I artificially interfere with tidal run, as TPXO files contain correct amplitudes already and I know that some researchers who run Telemac2D, for the same area, got good results without using this coefficient. Even when I run same case with Telemac2D, I got same bad results as for Telemac3d.

Also I have tried using coefficient to calibrate tidal range. The amplitude increased but not everywhere!? So I have started to suspect that my bathymetry file or boundary conditions might be wrong. The results are fine on one side of the boundary and wrong on other parts (the amplitude is 0 but should be 3-4 metres! even after using coefficient to calibrate tidal range). So it is probably bathymetry file that causes it.

I will try to get another bathymetry and then I will know for sure. I just hoped that maybe some numerical schemes I used in steering file might be wrong and then it would be easy to correct it. The JMJ data did not work for me well either as I am not sure if it covers that area.

Thanks.

Kind Regards!

Violeta

Hi Voileta,

Another factor which I reckon that may possible affect is the computational grid.
The grid may have to be refined is regions of sudden changes in bathymetry, or could it be that a more fine resolution grid may also possibly solve the problem.

If possible you may post the selafin file so that I may have a look at the mesh and the bathymetry.

With Best Regards,
Gourish

Great, thanks a mil Gourish. I have 1km everywhere in domain. It is a good idea to refine it. The quickest way would be if I refine it in whole domain for start. I will do so and re-run to see if it makes any difference. Thanks again for your valuable advice. I have attached the slf file if you could take a look at it when you get a minute. Thanks.

Kind Regards!

Violeta

Great, thanks a mil Gourish. I have 1km everywhere in domain. It is a good idea to refine it. The quickest way would be if I refine it in whole domain for start. I will do so and re-run to see if it makes any difference. Thanks again for your valuable advice. I have attached the slf file (and one as cfg type just in case if it is not attached) if you could take a look at it when you get a minute. Thanks.

Kind Regards!

Violeta

Hi Gourish,

Looks like file size is too big to post it on forum, is there other way I could send it to you? thanks.

Violeta

Hi Violeta,

You may use online file sharing service like
www.wetransfer.com/ to upload the file and then post the link over here.

If you have a gmail account then you can upload the file to google drive and publicly share the file, the share link can be posted here.

However please compress the file in zip or other compress format before sharing it.

With best regards,
Gourish

Hi Gourish,

Thanks a mil for your advice. I used wetransfer. I hope it works. Two files are there. One is .slf format and another one is slf.cfg just in case. Thanks again.


we.tl/ymU26yWyH7


Kind Regards!

Violeta