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icoFoam crash with unreasonable velocity.

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Old   November 19, 2011, 21:24
Default icoFoam crash with unreasonable velocity.
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Hello,

A question from an inexperienced OpenFOAM user.

I am playing around with a simple manifold design and icoFoam.

After 10 time steps everything looks more or less ok, but then suddenly the velocity increases to unreasonable values.

I increased the resolution of the mesh with unchanged results.

I have this problem generally with icoFoam that U increases until icoFoam crashes with a floating point error.

I understand I am doing something wrong, so if someone could point me in the right direction I would appreciate it.

Thank you.
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File Type: jpg Timestep_11.jpg (70.6 KB, 12 views)
File Type: jpg Timestep_11_U_max.jpg (61.0 KB, 11 views)
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Old   November 20, 2011, 19:38
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I think I found the reason for this problem.

After decreasing deltaT from 0.1 to 0.005 it seems to work good.

Could be useful for anyone else who stumbles upon this problem.
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Old   November 20, 2011, 21:48
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Alberto Passalacqua
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Hint: Check that the Courant number is < 1. If you need large time-steps, use pimpleFoam.
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