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Dear Developers and users,

I would like to simulate 2D river flow using TELEMAC2D.

If i want to use k-E model for solving turbulence, what are the relevant keywords i should make use of?

In case, i want to use any other turbulence model (Constant viscosity or Elder's or Smagorinsky), i would like to know the list of keywords associated with each and every model.

Thanks

Hello,

The TELEMAC-2D manual are pretty self explanatory on this aspect and others -- you can download these from this website at: telemac-2d

Hope this helps,
Sébastien.

Dear Developers and users,

For 2D river flow problem, i wish to use HAALAND'S LAW with FRICTION COEFFICIENT.

I also read the following in the manual (v6p2)

When evaluating the friction term, it is possible to specify which depth is used for this computation through the keyword DEPTH IN FRICTION TERMS. The two possibilities are: the classical nodal depth (value 1 which is the default), or a depth averaged on the test function area (value 2).

Can you explain me the difference between 'classical nodal depth' and 'depth averaged'?

Thanks
Sathya

Hello,

depth average depth on a test-function area is the integral of test-function * depth, divided by the area of the test-function. It is also the product of the mass matrix by the depth divided by the lumped mass matrix. It is an average between the nodal value and the values at neighbouring points.
Anyway this is of a lesser importance and you can stay with the default.

With best regards,

Jean-Michel Hervouet

Hello,

Thanks for your quick reply. I wonder why this option is available in TELEMAC if this is of lesser importance. The explanation what you gave explains only about depth average depth on a test-function area. However, I am still out of knowledge about what is classical nodal depth and how these two options differ from each other. I kindly request the you and members here to provide links/pointers to some literature/papers apart from Telemac User manual.

Thanks
Sathya

Hello,

This option has been tested to see its influence in situations with tidal flats. As for the nodal value of depth it is the value of depth at a node in the mesh, the very value that is used for finite element interpolation. So "nodal value" = value at a node, it cannot be more simple.

JMH

Dear developer,
In general, i understand that in order to form the basis function, space discretization can be done by choosing any one of the following options
1)Linear
2)Quasi-bubble
3)Quadratic
The last option(Quadratic) deals with the 6 nodes of the prism which is of three dimensions. Is this option only to be used in TELEMAC3D? Or we can use it in TELEMAC2D also?

Thanks

Hi

No you make a mistake.
In 2D, the space discretization gives the order of the basis functions.
For the quadratic, the order (2) requires 3 others points on the segments composing the triangle.
So the 6 points are the nodes of the triangle + one point in the middle of each edge
The Quasi-bubble is a 4 points / triangle discretization, the 4th point if the gravity center of the triangle which allow to divide each triangle in 3

Hope this helps

Hi developers and users,
Would you provide me the use of option 'CONSISTENT PROJECTION' in TELEMAC3D?
how does it affect the result(if not activated)?


Thanks
Sathya

Hello,

This keyword is not currently used. It consists in applying a strict variational formulation to the equation giving the final velocities once the dynamic pressure is known. It never gave a real improvement so we provisionally removed this option.

regards,

Jean-Michel Hervouet