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Old   August 16, 2017, 09:43
Default Simulation is deverging
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FFD
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Hello,
My simulation is deverges after 1 step. The AMG solver deverges. I guess the problem is my assumption for the turbulence.
I often get also the message that my turbulence viscosity is limited on many cells and that I have a reversed flow in some faces on pressure-outlet.

I use the k-omega approach.
My fluid flows in a helix. 2 meters long with a diameter of 55mm and 30 revolutions. So I calculated the length of my fluid area, which would be when I would have a straight line instead of the helix. My value was about 5.55m.
With water as fluid and 1m/s free stream velocity I calculated my tke(0.0007917900792802) and sdr(0.0000038681421927). My simulation still deverges pretty fast. After 1 iteration I get the error message that the AMG solver for temperature doesn't converges.

My models are:
Energy equations - on
Viscous model - k-omega standard
rest is default
My inlet is a velocity inlet with 1m/s and the given tke and sdr
My outlet is a pressure outlet with 0pa and the given tke and sdr
My solution methods are not clear now. I tied it with all best approaches (like 3rd Order stuff) and standard methods. Always the same results.
Solution controls are standard.
Solution initialization is standard with my values taken from the inlet.

Any suggestions?

Best regards FFD
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