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Hi everyone,

I am a beginner in t2d and I am building my first model. I'm finding some troubles with the boundary conditions. The model is set up in the Hooghly estuary and therefore all the BC are influenced by the tidal behavior. Then I set 3 BC lines with prescribed U, V and H (566).

The idea of the simulation is to work with a real tide, in this case read from the TPXO databases. To do so, I downloaded the bin format file - Indian Ocean 1/12° from www.tpxo.net/regional . I also set the Initial Conditions to be read from TPXO.

The simulation run stable. The initial conditions seem to be respected, but the Boundary conditions don't seem to be read, and therefore in the run log (CMD) it is possible to see that there is not water entering nor leaving the domain, for all the time steps. The results in BlueKenue do not show any change during the 16h40min simulation This can be seen in the image.



I would like ask you to point me out if my problem is the type of BC im selecting, or the data I am providing (OSU-TPXO). Or if there is another reason why this is happening.

I attach the steering file so you can check the configs.


Hope you can help me.

Hi
Are you sure about the initial condition?
The picture of free surface look strange with a kind of step...
Problem with the bathymetric data?

Moreover, you have to check the area covered by tpxo to ensure there will be values upstream...

Regards

Hi, first of all thank you for your answer.

I checked about the initial condition (IC), I changed the date of the simulation to 2022;10;22, and the model starts with a different set of initial elevations, so it seems to be right (see image ). I think the previous screenshot looked like a'step', but it was just about the resolution of the TPXO data for IC for a specific time.
I also checked the elevations from bathymetry and it seems to be right aswell. The image also shows the bathymetry with negative values since it is an estuary model.

Regarding the position and if it is covered by the TPXO, I am having some troubles doing that check. I am working with the UTM model zone 45, and the simulation place is in the mouth of the Hooghly river. In the image attached (top right) shows an image from www.tpxo.net/regional

I downloaded the Indian Ocean 1/12° bin file from OSU TPXO, and I am using those (.out) files as the binary files.
BINARY DATABASE 1 FOR TIDE : hf.IO_2010.out
BINARY DATABASE 2 FOR TIDE : uv.IO_2010.out

But I don't know how can I open the .out files to visualize what is in them.

I know those are a lot of questions, but those are the sections in which I think the error can be found. Any suggestion, correction or anything will be highly appreciated.


Best regards,
Jorge Sanabria.

Hello Jorge,

I would start by increasing the extent of your domain, in particular to move your tidal boundary condition further south. In your case, it is only about 10 km from last island, I would try 30 km or even 50 km (perhaps a little bit more like 70km).
Indian Ocean regional solution may not have quite accurate values so close to the coast (10 km).

In the output file, at the beginning of the simulation (just run 1 time step e.g.), do you have writing like:
WARNING!!! THE POINT WITH X/Y IN THE MESH =
CONVERTED TO LONGITUDE/LATITUDE =
SEEMS TO BE OUTSIDE OF THE EXTENT OF THE TIDAL SOLUTION
WHOSE MIN/MAX FOR LONGITUDE ARE:
CHECK THE KEYWORDS GEOGRAPHIC SYSTEM + ZONE NUMBER IN GEOGRAPHIC SYSTEM =

If you have some lines like this, it could be an issue of location.

Hope this helps,

Chi-Tuan

Hello, sorry for the late reply, but I wanted to make sure I tested enough before coming here. Firstly, thank you for the advices.

Well I finally solved my problem, turns out my error was in the very basics of the model, in the geometry.
I had created the friction coefficient based on the dephts values of bathymetry to try to take into account the depth of water; and as i had some depths at exactly 0 m, some of the friction coefficient also get to be exactly 0. Then, even when the simulation started, it was not performing well the calculations and it was showing me NaN on the mass balance's flux boundarys values.

Also, I tested both the IO.2010.out and the tpxo7.2 files for the BINARY DATA BASE FOR TIDE and both run giving slightly different results.

I don't recall right now any other important detail that I can leave here as feed back but if I remember something extra I will share.

Thank you very much, best regards.