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velocity is too fast (?)

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Old   September 29, 2010, 10:33
Default velocity is too fast (?)
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I'm not sure whether this is the right topic or not for I assume the failure is some where in the pre processoring part, but I discovered it in the post processing part, so I write it down here.

The problem:
I run a simulation with the rasInterFoam solver
The case is fairly simple a floating structure in a domain that is divided in an air part and a water part. The water shall enter the domain with a speed of 8m/s through an inlet patch and leave it through an outlet patch.
to quickly see if everything works out fine before I really let the simulation run I choose a total simulation time of 0.03 in the steps of 0.001 starting with 0.
According to simple mathematics a piece of wood starting at the inlet can travel only 0.24m within that given time and speed, neglecting any side effects.
But according to paraview it traveled around 40m and more.

So my question is: what?? how can that be??

I attached a file showing the paraview visualization
key data
domain size in x direction 350 m
velocity 8 m/s
timestep 0.03 is printed

If you have some further questions do not hesitate to ask me

thanks for your trouble

Attached Images
File Type: jpg velocity_to_fast.jpg (50.4 KB, 8 views)
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