Access to the nodes velocity at the end of an increment


I’m working on coupling Calculix to a Fluid solver in order to perform Fluid Structure Interaction.

For this purpose, I need to get the positions and velocities of the nodes at the end of each increment.

In the Calculix Manual, they give in “10.15 List of variables and their meaning”

“v(i,j) displacement of node j in direction i at the end of an iteration”

“ve(i,j) velocity of node j in direction i at the end of an iteration”

I only use the explicit solver so I think there is no difference for me between “end of an iteration” and “end of an increment”.

I don’t have problem to get “v(i,j)” but in reality the source code doesn’t mention “ve(i,j)” so I’m wondering if someone know how to get access to the velocity of the nodes at the end of an increment ?

(I would rather use the exact velocity from calculix and avoid recalculating by myself the velocity from the displacement)

Thank for your help

Do you want to couple the solvers manually ? Which software do you use for flow calculations ? There are some ready-made solutions for FSI with CalculiX (such as preCICE).

Yes I have already seen the work from precice on Calculix but they are only interested in the position of the nodes and not about the velocity contrary to me.

I’m using a lattice boltzmann solver, I have already developed the coupling and it is working but I can’t have the “real” velocity of the node at the end of the iteration…

Look for the variable veold.

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