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Hi,

I am using mattise to make both geometric and conlim files which are giving in to the cas file.I want to run TOMAWAC module for my study area. it is a 4 side square type. it has one contour ar 10 meter,one at zero depth and other two are line connecting between these two 10 meter and 0 meter depth line.Please help me to define these boundaries. For this what are the conditions to give for these three boundaries when we are generating create entity.

Thanks with warm regards.

Hello,

apologizes for the late answer.
You asked a similar question in another post.
I just copy and paste the answer to that post :

The boundary conditions are used for two purposes :

• to impose a wave energy flux entering the model domain (in this case you must set the value 5 in the first column of the boundary conditions file)
• to represent solid absorbing (islands, coasts)and in some cases liquid boundaries along which the wave energy can only exit and cannot enter (in this case the value to set is 2).

So, via the boundary conditions you set where wave energy flux enters or is absorbed in the model domain.
If you do not set any boundary conditions there is not wave energy entering the model, i.e. during the simulation the wave height tend to zero, unless you impose a forcing wind over the domain.

Kind regards,

Giovanni

Hai Geovanni

Thanks for your reply. I will contact you if there is any error and doubt related to the modelling work using Tomawac.

Thanks and Warm regards.

Glejin

Hai,

Still I have some confusion with initial and boundary conditions.Is there any relationship with initial and boundary main direction?. if yes what is the relationship between these two direction parameters? what is the term boundary main direction? Is it related to coast inclination to true north?

Thanks
Glejin

Hello,

I guess you want to simulate an offshore sea state that propagates towards the coast.
In this case you should set:

• the 0 m contour line as a solid absorbing boundary
• the other three boundaries as boundaries across which a not null wave energy flux enters the domain.

To do so, you can either create a .conlim file via Matisse, or modify an already existing .conlim file of the model to impose the above conditions.

In the first case, when you create an entity in Matisse you have to set:

• the solid wall conditions for all the four variables H, U, V and T for the solid absorbing boundary
• imposed H, free U, V, and T for the three other boundaries.

In the second approach (modification of the .conlim file), you have to:

• set the value 2 in the first column of the boundary conditions file, for representing the solid absorbing boundary
• set the value 5 in the first column of the boundary conditions file to represent the wave energy flux entering the three other boundaries.

Hope it helps.
Kind regards,

Giovanni

Hai....

I used the things what you mentioned above in this topic.I have no confusion on setting boundary conditions using mattisse for solid and liquid boundaries.I have doubt only about the values are giving in the steering file as initial and boundary condition parameters.There is any relationship between the values of boundary and initial condition parameters in the cas file. On what basis we are giving the values for boundary and initial condition parameters.

Regards

Glejin

Hello,

The boundary condition parameters define the sea-state conditions set at the boundaries and that are propagated into the model domain during the simulation.

The initial conditions define the sea-state conditions INSIDE the model domain at the simulation time t=0.

There is not a relationship between initial and boundary conditions (of course if you impose a wave height of 1m at the boundaries, it does not make lot of sense to impose a wave height of 10m in the domain as initial condition).

Kind regards,

Giovanni

Hai,

Thank you for your information.Ihis time I have some doubt on the theory side of TOMAWAC modelling.Manual is saying that "spatial transfer rates model the spatial wave propagation and the shoaling.The directional transfer rates model the refraction induced change of wave propagation direction" . So I am interested to know the calculation of wave propagation and shoaling from the transfer rates,(x,y,and Theta). And I am interested to know more about the transfer rates, what does it physically means.

Glejin

Thanks

Hai all,

I need someone's help please.

regards,
Thanks,

Glejin

Hello,

if you refer to the equation 4.11 in the TOMAWAC guide, the transfer rates along x and y represent the x- and y- components of the propagation velocity of the wave energy in a fixed frame of reference (in the case of no current, this corresponds to the x- and y- components of the group velocity).
The directional transfer rate represents the rate of change of the wave direction due to the refraction induced by the depth (first term on the right-hand side of equation 4.12c) plus the refraction induced by the current (second term on the right-hand side of equation 4.12c).

Hope it helps.
Kind regards,

Giovanni