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defining a surface in 2d axisymmetric

Posted 11 feb 2015, 18:36 GMT-5 5 Replies

Maryam Abd
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Hi,

if I want to calculate the heat flux that is exchanged by the bottom and the top parts of a cylinder, how can I define the surfaces at the top and bottom in a 2d axisymmetric? by cut line 2D or Cut plane 1?
5 Replies Last Post 13 feb 2015, 12:07 GMT-5
Lasse Murtomäki
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Posted: 9 years ago 12 feb 2015, 01:51 GMT-5
Cut line, calculate line integral, but click the box "Compute surface integral". But if it is the bottom or top of your cylinder, cut line is naturally not needed.

br
Lasse
Cut line, calculate line integral, but click the box "Compute surface integral". But if it is the bottom or top of your cylinder, cut line is naturally not needed. br Lasse
Maryam Abd
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Posted: 9 years ago 12 feb 2015, 12:32 GMT-5
So if I just go to a" line integration" and in "selection" I select top and bottom, and in "Expression "part I choose "ht.tefluxMag" it will calculate the amount of heat calculated from top and bottom?

also how can I compare the heat flux in the radial direction and in the z direction?

Thank you very much,
Maryam
So if I just go to a" line integration" and in "selection" I select top and bottom, and in "Expression "part I choose "ht.tefluxMag" it will calculate the amount of heat calculated from top and bottom? also how can I compare the heat flux in the radial direction and in the z direction? Thank you very much, Maryam

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Lasse Murtomäki
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Posted: 9 years ago 12 feb 2015, 14:52 GMT-5
Line integration with surface integration gives heat flux across that surface. Selecting top and bottom just gives their sum, not flux from top to bottom.

Under Domain fluxes you can find contribution to r, z and phi directions. Across the boundary only the normal flux matters.

br
Lasse

Line integration with surface integration gives heat flux across that surface. Selecting top and bottom just gives their sum, not flux from top to bottom. Under Domain fluxes you can find contribution to r, z and phi directions. Across the boundary only the normal flux matters. br Lasse
Maryam Abd
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Posted: 9 years ago 13 feb 2015, 08:45 GMT-5
so if I want to define the surface around the cylinder(not top and bottom of the cylinder) how can I do that?



Thank you,
Maryam
so if I want to define the surface around the cylinder(not top and bottom of the cylinder) how can I do that? Thank you, Maryam
Lasse Murtomäki
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Posted: 9 years ago 13 feb 2015, 12:07 GMT-5
Since your model is axisymmetric, any vertical line actually represent a cylinder surface. If you want to calculate heat flux across a cylinder, calculate again a line integral over this line and activate again "Compute surface integral".

Did I understand you correct?

best regards
Lasse
Since your model is axisymmetric, any vertical line actually represent a cylinder surface. If you want to calculate heat flux across a cylinder, calculate again a line integral over this line and activate again "Compute surface integral". Did I understand you correct? best regards Lasse

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