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temp contour lines are not continuous at the interface of 2 zone!! [PLEASE HELP]

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Old   March 1, 2016, 10:52
Lightbulb temp contour lines are not continuous at the interface of 2 zone!! [PLEASE HELP]
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Hadi
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Hi guys,

i got a weird problem !!!
i wanna simulate a 3D equilateral triangular duct which is consisted of 2 zone. (i made it 2 zone since i wanna use lower zone for porous media.)

the problem is when i make the duct into 2 zone, the temp contour lines is not gonna be continuous at the interface of 2 zone, even if the 2 zone have the same properties and inlet and outlet conditions!

BUT if i merge 2 zone into 1 zone (or simply delete all cell zone boundary in GAMBIT), the problem will be solved. BUT I NEED 2 ZONE because i want to use porous media for another zone !!!

take a look please at pics below for more understanding of the problem:

schematic


temp contour (see the interface between 2 zone)



please please help, i would be so grateful
many Thanks in advance.
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Old   March 1, 2016, 17:11
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Quote:
Originally Posted by Hadi Khabbaz View Post
Hi guys,

i got a weird problem !!!
i wanna simulate a 3D equilateral triangular duct which is consisted of 2 zone. (i made it 2 zone since i wanna use lower zone for porous media.)

the problem is when i make the duct into 2 zone, the temp contour lines is not gonna be continuous at the interface of 2 zone, even if the 2 zone have the same properties and inlet and outlet conditions!

BUT if i merge 2 zone into 1 zone (or simply delete all cell zone boundary in GAMBIT), the problem will be solved. BUT I NEED 2 ZONE because i want to use porous media for another zone !!!

take a look please at pics below for more understanding of the problem:

schematic


temp contour (see the interface between 2 zone)



please please help, i would be so grateful
many Thanks in advance.
are you using conformed mesh? are you plotting cell or node values? This might be caused because of the interpolation fluent does between the 2 zones.
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Old   March 1, 2016, 17:48
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Originally Posted by Bruno Machado View Post
are you using conformed mesh? are you plotting cell or node values? This might be caused because of the interpolation fluent does between the 2 zones.
thx for the response

actually i tested it with different kinda mesh and somehow i came to conclusion that mesh is not responsible for the problem.

i use "Tecplot 360 EX 2015 R2" for the contours. i dont know exactly how to use "cell" value or "node" value for contour in tecplot. i use Tecplot default setting and i use "slices" option in TecPlot to make a 2D contours at the middle of 3D duct.

could u pls walk me through how use cell or node values in tecplot

thx in advance
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Old   March 1, 2016, 17:52
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Quote:
Originally Posted by Hadi Khabbaz View Post
thx for the response

actually i tested it with different kinda mesh and somehow i came to conclusion that mesh is not responsible for the problem.

i use "Tecplot 360 EX 2015 R2" for the contours. i dont know exactly how to use "cell" value or "node" value for contour in tecplot. i use Tecplot default setting and i use "slices" option in TecPlot to make a 2D contours at the middle of 3D duct.

could u pls walk me through how use cell or node values in tecplot

thx in advance
I can not help you because I do not use tecplot as post processing software. But inside Fluent, plot the contour you want and uncheck the node values option and see if you are getting the same problem as in the tecplot. If not, search on this forum how to extract data from without using node and post process it on tecplot.
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Old   March 6, 2016, 11:28
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It's a tecplot problem and could be from several causes but it's basically an interpolation problem.

It could be tecplot is missing the data along the boundary because you only exported the cell data and not face data. Tecplot has to interpolate from the two zones.
It could also be the cell gradient calculation, tecplot does it's own thing and then extrapolates to cell boundaries.
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Old   March 8, 2016, 20:10
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Quote:
Originally Posted by LuckyTran View Post
It's a tecplot problem and could be from several causes but it's basically an interpolation problem.

It could be tecplot is missing the data along the boundary because you only exported the cell data and not face data. Tecplot has to interpolate from the two zones.
It could also be the cell gradient calculation, tecplot does it's own thing and then extrapolates to cell boundaries.
yeah it was tecplot problem exactly! i had to use another method to use tecplot or have to use another post process software
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