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Discontinuity in Shear Stress Profile - Single Phase Rotating Machinery

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I attached two compared images. My model is very similar to comsol's
Baffled reactor model (my geometry is different). It's a Single Phase Flow, Rotating Machinery and I set two domains - rotating inner domain and fixed outer domain coupled by an Identity Pair (Flow Continuity)

With my model, unlike the comsol's 'baffled reactor model', I get a big discontinuity in shear stress (top view, volume mode, Expression:rmspf.sr*eta) between the fixed outer domain and the rotating inner domain. Something must have gone wrong in my model because the baffled reactor example has continuous shear stress gradient (over this boundary line between outer and inner domain).
To see this continuous profile, please change the manual colour range of the shear volume to Maximum:0.04.

The actual name of the comsol model is "Laminar Flow in a Baffled Stirred Mixer.
www.comsol.com/showroom/documentation/model/8559/
I attached this model with solver deleted.

Could you suggest me what could be the problem?
Thank you!



1 Reply Last Post 2011年8月25日 GMT-4 02:39

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Posted: 1 decade ago 2011年8月25日 GMT-4 02:39
Hi,

Difficult to say much without looking at your model. One thing I can notice is that whereas in the comsol model the stress is localized close to the moving parts, in your model, if I understood correctly, the stress is max close to the non-moving walls. I would have a look at the boundary conditions and the identity pair.

Cheers
Hi, Difficult to say much without looking at your model. One thing I can notice is that whereas in the comsol model the stress is localized close to the moving parts, in your model, if I understood correctly, the stress is max close to the non-moving walls. I would have a look at the boundary conditions and the identity pair. Cheers

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