[soufiane002]

hello every one
i want help please
i want to create a 2d cavity with a triangular wall like in the picture


if someone have an idea how to generate the periodic triangular wall please help

[vesp]

homework problem? In any case, what are you asking? How to create the geometry? mesh? or the boundary conditions?

[soufiane002]

Originally Posted by vesp

homework problem? In any case, what are you asking? How to create the geometry? mesh? or the boundary conditions?

I am asking how to create the geometry
Thanks

[vesp]

Originally Posted by soufiane002

I am asking how to create the geometry

Thanks

geometrically? That seems simple enough... I guessI still do not understand what you are asking. Could you be more specific?

[soufiane002]

Originally Posted by vesp

geometrically? That seems simple enough... I guessI still do not understand what you are asking. Could you be more specific?

i want just to know how to create the triangular wall in my geometry if there is a function that i can use to generate the triangular wall in function of y or x


thanks

[sbaffini]

Are you using a specific software? Maybe that has a dedicated forum here.

Also, geometry means nothing. Do you need the geometry in some specific format, or the mesh in it (and which format)?

If you are doing it from scratch in fortran, I guess you have little chances, because it is clear that those are piecewise linear functions and you will face much harder problems along the route.

Moreover, the problem is symmetric, you just need half of that.

[soufiane002]

i think my question wasn't clear enough
i think the geometry and the mush are related
so i have done with corrugated wall by using a sin function to generate the mush

now i want to change the wall to periodic triangular like in the picture above

i'm doing it from scratch in fortran.

thank you all.

[sbaffini]

Originally Posted by soufiane002

i think my question wasn't clear enough
i think the geometry and the mush are related
so i have done with corrugated wall by using a sin function to generate the mush

now i want to change the wall to periodic triangular like in the picture above

i'm doing it from scratch in fortran.

thank you all.

Let me see If I get it correctly:

you already have a mesh generator in Fortran for a case very similar to the one depicted in the picture you posted, but with a sinusoidal top boundary.

You have a function, the sin indeed, that is used to generate the top part of your domain and whatever is linked to it.

You are looking for some mathematical function that, once inserted in the place of the sin one, would change your top boundary and the resulting mesh in the one for the triangular top boundary.

Now, this is very clear, but I'm not sure you can get the expected result without trouble. Nonetheless, the obvious option here would be to define your own Fortran function ytop(x,other_parameters) and do everything in that.

You can basically code your function in a thousand ways, just check here:

https://en.wikipedia.org/wiki/Triangle_wave

EDIT: note how you can get almost there also using just 3 harmonics of the Fourier representation (in case it might be a problem for your code to have singularities in the top boundary).

[soufiane002]

Originally Posted by sbaffini

Let me see If I get it correctly:

you already have a mesh generator in Fortran for a case very similar to the one depicted in the picture you posted, but with a sinusoidal top boundary.

You have a function, the sin indeed, that is used to generate the top part of your domain and whatever is linked to it.

You are looking for some mathematical function that, once inserted in the place of the sin one, would change your top boundary and the resulting mesh in the one for the triangular top boundary.

Now, this is very clear, but I'm not sure you can get the expected result without trouble. Nonetheless, the obvious option here would be to define your own Fortran function ytop(x,other_parameters) and do everything in that.

You can basically code your function in a thousand ways, just check here:

https://en.wikipedia.org/wiki/Triangle_wave

EDIT: note how you can get almost there also using just 3 harmonics of the Fourier representation (in case it might be a problem for your code to have singularities in the top boundary).

yes this is exactly my problem