@@ -19,6 +19,8 @@ In the data which you cloned you will find the `dem.input` file with the experim
You also get a `wave.input` file containing a time-series definition of the input wave which serves as a forcing boundary and drives the tsunami into the computational domain. You can also inspect this text file, which has a very simple and human readable structure.
Finally, you get the `polygon.input` file which defines the geometry for the boundary in which the wave flows in.
## What's missing?
For all the points herein, you can refer to the aforementioned [Quick tutorial: setup a model](https://gitlab.com/serghei-model/serghei/-/wikis/User-Guide/Quick-tutorial:-setup-a-model#Simulation-Control) page for details.
...
...
@@ -39,7 +41,8 @@ We will run this test on a single compute node, therefore ***no domain decomposi
We will use `NETCDF` output, default boundaries should be `REFLECTIVE`, and a reasonable screen output is between 200-1000.
## Shallow water model control `sw.input`
The initial conditions for the experiment are those of a quiescent (i.e., zero velocity) water surface at sea level. In the typical shallow water variable naming `h` is water depth, `z` is the elevation of the bed relative to some arbitrary datum, and therefore `h+z` is the elevation of the water surface relative to the same datum. This datum must be consistent with that of the DEM. In the DEM `z=0` is the mean sea level. With this information, set `initialMode` and `initialValue`.
The initial conditions for the experiment are those of a quiescent (still water) water surface. That is, we want a horizontal water surface at sea level with zero velocity.
In the typical shallow water variable naming `h` is water depth, `z` is the elevation of the bed relative to some arbitrary datum, and therefore `h+z` is the elevation of the water surface relative to the same datum. This datum must be consistent with that of the DEM. In the DEM `z=0` is the mean sea level. With this information, set `initialMode` to `h+z` and `initialValue` to sea level.
This benchmark typically uses Manning's friction law, with a roughness value of 0.01. Set this up in the file. Finally, because of the small scale of the experiment, and because in a tsunami we are particularly interested on the advancement of the wave over dry land, we will use a dry depth tolerance of 0.0001 m.
...
...
@@ -85,14 +88,13 @@ Nonetheless, it is important to highlight that still water equilibrium is a very
# 6. Run the full simulation
Now we want to run the full simulation, with boundaries which model the incoming tsunami wave. For this we need to create the `extbc.input` file (`extbc` stands for external boundary conditions).
Details on how to setup boundary conditions are in the [SERGHEI BC wiki page](https://gitlab.com/serghei-model/serghei/-/wikis/User-Guide/Boundary-conditions).
Details on how to setup boundary conditions are in the [SERGHEI BC wiki page](https://gitlab.com/serghei-model/serghei/-/wikis/User-Guide/Boundary-conditions). Try setting this up simply following the documentation.
We need to devine a single boundary, which we may call `inlet`. We wish to define an **inflow stage hydrograph**, i.e., a time series of water surface elevations (t, h+z). You therefore need to include the relevant `bctype` code for this. `direction` indicates the inflow direction of the hydrograph in a unit vector fashion, i.e., `1.0 1.0` would mean a 45 degree angle (North-East), `-1, 0` would mean a 180 degree angle (South).
Finally, the `polygon` and `hydrograph` entries require the name of the polygon file which defines where to find the boundary, and the file containing the stage hydrograph (i.e., `wave.input`).
Finally, the `polygon` and `hydrograph` entries require the name of the polygon file which defines where to find the boundary (`polygon.input`), and the file containing the stage hydrograph (i.e., `wave.input`).
Try to build the polygon file to capture the west boundary, where the tsunami wave should come from, flowing eastwards.
Try to understand how the polygon encodes the information. It defines a polygon which envelopes the west boundary (`x=0`), where the tsunami wave should come from, flowing eastwards.
Once all this is setup, run the simulation again and visualise the results again. If everything is set correctly, results at the end of the simulation should look like this
