icoFoam crash with unreasonable velocity.

Bylund · November 19, 2011, 20:24

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.

Bylund · November 20, 2011, 18:38

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.

alberto · November 20, 2011, 20:48

Hint: Check that the Courant number is < 1. If you need large time-steps, use pimpleFoam.

November 20, 2011, 18:38		#2
Bylund New Member Join Date: Jun 2010 Posts: 6 Rep Power: 15	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. __________________ Mechanical Engineer

November 20, 2011, 20:48		#3
alberto Senior Member Alberto Passalacqua Join Date: Mar 2009 Location: Ames, Iowa, United States Posts: 1,912 Rep Power: 36	Hint: Check that the Courant number is < 1. If you need large time-steps, use pimpleFoam. __________________ Alberto Passalacqua GeekoCFD - A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as in both physical and virtual formats (current status: http://albertopassalacqua.com/?p=1541) OpenQBMM - An open-source implementation of quadrature-based moment methods. To obtain more accurate answers, please specify the version of OpenFOAM you are using.

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