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 Vlad Miryaha November 12, 2012 19:46

"solidDisplacementFoam" solver usage

Hello,
in the paper http://powerlab.fsb.hr/ped/kturbo/op...tresspaper.pdf
it`s written, that
"The initial condition consists of specified distribution of u and du/dt at time zero."
I think that the paper authors use "solidDisplacementFoam" solver.

Does anybody know how to set initial du/dt distribution???

TIA

 Hisham November 12, 2012 20:43

The solver in question is to my understanding solidDisplacementFoam as you mentioned. Currently, I think it is not possible to introduce initial velocity. I am not aware of the initial version where that was possible. Nevertheless, you can introduce a new volVectorField called initialVelocity that is read from a dictionary and add a term to the equilibrium equation that is fvc::ddt(initialVelocity) ... I do not know if this is a proper way for your application but if you can explain more about your problem maybe you can get better help!

Best regards,
Hisham

 Vlad Miryaha November 13, 2012 07:21

At this moment I`m doing some test computations of transient wave propagation in a cube (1m*1m*1m).
At time zero initial displacement at one side is set. (I want to see a compression plane wave propagetion and a reflection from opposite side).
Wave propagates and it`s reflected, but it becomes smearing.
Wave becomes smearing even before it reachs opposite side.
Boundary conditions are set to zeroGradient (I tried symmetryPlane too).
The value of "relTol" and "nCorrectors" in fvSolution file are set to 0.01 and 10 respectively.
Approximation orders in fvScheme file are set to cubic/fourth for spatial derivatives.

I can`t understand the reason of such significant smearing.

I hope that if I set initial velocity instead of displacement result becomes better.

 Hisham November 13, 2012 09:21