open TELEMAC-MASCARET The mathematically superior suite of solvers

hello !

I would like to add specific behavior to the drogues/particles released in TELEMAC-3D (i am using the last version v7p2r1)

I think I should do it in FLOT3D.

Among the behavior, i would like to add a settling velocity.

Is anyone have already done such modification ?

Thanks for your help !
Vincent

Hello,

The settling velocity is not implemented in the Lagrangian tracking (for sediment it is done in a eulerian way). It would require using a modified vertical velocity W*. There are two possibilities to do that:

* A post-treatment of the call to SCARACT which computes the trajectories. Knowing the arrival position of the particle, you just have to shift it down, which will change only the element number and vertical coordinate.

* An extra call of SCARACT with the modified velocity W* (a theoretical derivation is probably necessary to know the effect of the settling velocity on W*, in generalised sigma transformation it will depend on the layer considered).

The first is more straightforward to implement, the second will give faster code.

With best regards,

Jean-Michel Hervouet

Thanks for your help Jean-Michel !

However, I am not sure to have the time and the skills to do such modification for the moment

Actually I meant:

"The second is more straightforward to implement, the first will give faster code". For shifting down the particles, it just requires to understand how is stored the position of a particle, namely only the element number and value of vertical local coordinate ETA have to be changed, maybe not so difficult.

Regards,

JMH

some tests have to be done in order to shift down or not the particles, depending on the settling velocity and the current vertical layer.
But you are right, it is not difficult