VOF error when initializing
When initializing turbulent flow for VOF calculation, solver get me this error:
"Warning: Initializing turbulent flow with density unavailable in fluid! Density of 1 kg/m^3 assumed for computing initial turbulence quantities." What is it?? How can I avoid this error?? Thank a lot |
Re: VOF error when initializing
There's no problem, simply the turbulent flow field will be initialized using a standard density value. Next the turbulent flow will be calculated coerently with the exact density of the fluid...
It's just the initialization |
Re: VOF error when initializing
...ok, but after a few iteration simulation diverge and the iso-surface at VOF=0.5 assume unphysical shape....
With laminar model I don't have this problem! Any idea?? |
Re: VOF error when initializing
what kind of simulation is? Steady, transient...and also: underelax, boundary, initialization field/functions...?
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Re: VOF error when initializing
Simulation is VOF unsteady, underelax low (0.4, 0.3 etc..), wov wave first order, 6DOF frozen for computing hyrodynamics forces on a ship hull.
Similarly of the demo from CD-Adapco for DFBI, i set the correct bondary conditions, but i change turbulent model...so from laminar to k-omega. Mesh is ok, with B.L.y+=50. Time step 0.01s Do you have any experience on this problem? |
Re: VOF error when initializing
Are you using first or second order time Discretization?
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Re: VOF error when initializing
second order
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Re: VOF error when initializing
and first order for time!
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Re: VOF error when initializing
Try changing the turbulence specification to K + Epsilon on both the initialization and the inlet.
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Re: VOF error when initializing
if it doesn't work try initializing the sim with first order scheme...then switch to second order later
It's a general tip, I'm sorry but I don't have experience in this kind of sim...but the initialization it's similar to other ones... |
Re: VOF error when initializing
Have you tried lowering the time step? Are you using ccm+ or v4? In v3 I always faced problem when the time step is that large (0.01s). In v4 this seems less a problem. I think I read on the manual or somewhere VOF is not yet able with k-omega or other turbulence models. For DFBI, it might not even able to handle k-E but I'm not sure. BTW, I'm curious to know how long it takes you to complete this run.. the elapsed time I mean... when you complete this job later. (Just curious if you dont mind).
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Re: VOF error when initializing
I think VOF and turbulence don't go together in STAR-CD. The software calculates granular variables and the only correct choice there is laminar flow.
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