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how to get the average values on parallel channels

Posted Nov 15, 2012, 6:53 a.m. EST Results & Visualization Version 4.3 7 Replies

Yuanhai Su
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Hello everybody. Now I simulate the hydynamics of the distributor with parrallel channels. I want to get the mean velocity values in the middle of each channels. I try to use the 'cut plane' on the postprocess, but this operation will create the surface for all parrallel channels. So it doest not get the value for each channel. The geometry is like the attached document.

Thank you for your help!!

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7 Replies Last Post Nov 18, 2012, 7:07 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Nov 15, 2012, 9:18 a.m. EST
Hi

I beleive the easiest is to cut your geoemtry so you have some useful internal boundaries at each inlet/outlet for all your U shapes, then youcan select the different boundaries. The geoemtry is slightly more complex, the model too, but it's far easier to work and postprocess like that

--
Good luck
Ivar
Hi I beleive the easiest is to cut your geoemtry so you have some useful internal boundaries at each inlet/outlet for all your U shapes, then youcan select the different boundaries. The geoemtry is slightly more complex, the model too, but it's far easier to work and postprocess like that -- Good luck Ivar
Yuanhai Su
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Posted: 1 decade ago Nov 15, 2012, 9:27 a.m. EST
Mr. Ivar, Thank you so much! I will try it.









Hi

I beleive the easiest is to cut your geoemtry so you have some useful internal boundaries at each inlet/outlet for all your U shapes, then youcan select the different boundaries. The geoemtry is slightly more complex, the model too, but it's far easier to work and postprocess like that

--
Good luck
Ivar


Mr. Ivar, Thank you so much! I will try it. [QUOTE] Hi I beleive the easiest is to cut your geoemtry so you have some useful internal boundaries at each inlet/outlet for all your U shapes, then youcan select the different boundaries. The geoemtry is slightly more complex, the model too, but it's far easier to work and postprocess like that -- Good luck Ivar [/QUOTE]
Yuanhai Su
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Posted: 1 decade ago Nov 15, 2012, 9:34 a.m. EST
Mr.Ivar,

I try it again. I used the section of 'derived values" after creating the surface. Unfortunately, I can not get the independent values for each channel. I only get the mean value for the parrallel channels. Maybe I misundertood you? Thank you.
Mr.Ivar, I try it again. I used the section of 'derived values" after creating the surface. Unfortunately, I can not get the independent values for each channel. I only get the mean value for the parrallel channels. Maybe I misundertood you? Thank you.
Yuanhai Su
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Posted: 1 decade ago Nov 17, 2012, 5:20 p.m. EST
Could every one help me on this issue. Thank you!
Could every one help me on this issue. Thank you!
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Nov 18, 2012, 4:41 a.m. EST
Hi

If you use a "cut plane" in the Data set, you need to combine in many bolean values to get the local avarages (and you should not use the average operator, as this will average over the full area).

Threfore, in such cases I split the pipes in the geometry as sections od domains with defined interna boundaries where I want to measure some value. The in the Derived Variable section you can select one boundary after the other and ask for the local average of any flux or variable value

--
Good luck
Ivar
Hi If you use a "cut plane" in the Data set, you need to combine in many bolean values to get the local avarages (and you should not use the average operator, as this will average over the full area). Threfore, in such cases I split the pipes in the geometry as sections od domains with defined interna boundaries where I want to measure some value. The in the Derived Variable section you can select one boundary after the other and ask for the local average of any flux or variable value -- Good luck Ivar
Yuanhai Su
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Posted: 1 decade ago Nov 18, 2012, 6:35 a.m. EST
Dear Mr. Ivar

Thank you! You mentioned that I should split the whole geometry with internal boundary. It seems a good strategy. Do you have other solution to this issue if the geometry is not created as separated parts? Because now I had finished the simulation on the whole geometry.
Dear Mr. Ivar Thank you! You mentioned that I should split the whole geometry with internal boundary. It seems a good strategy. Do you have other solution to this issue if the geometry is not created as separated parts? Because now I had finished the simulation on the whole geometry.
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Nov 18, 2012, 7:07 a.m. EST
Hi

you can add a few workplanes and apply some surface/rectangles that cut your domain (even if your main geometry is imported from a CAD system) then the default "union" mode of the Geometry Finish node should decompose your domain/BCs accordingly.

Not that this might well change the domains ID's so you must carefully go through all nodes to check these apply to the correct domains/boundaries, as COMSOl might get mesed up in the internal entity ID data base

--
Good luck
Ivar
Hi you can add a few workplanes and apply some surface/rectangles that cut your domain (even if your main geometry is imported from a CAD system) then the default "union" mode of the Geometry Finish node should decompose your domain/BCs accordingly. Not that this might well change the domains ID's so you must carefully go through all nodes to check these apply to the correct domains/boundaries, as COMSOl might get mesed up in the internal entity ID data base -- Good luck Ivar

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