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Old   October 29, 2012, 08:06
Default heat transfer distribution
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I have simulated problem , the base of channel is a heat transfer source ( constant ) , when i plot the total surface heat transfer flux at this section ( the base of the channel ) , its appear as a constant line exept at the end and beginning of the channel ?! i need sombody help me why this happen ??

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Old   October 30, 2012, 00:08
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can somebody get me some help ??
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Old   October 30, 2012, 01:04
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Hi,

What is the type of BC you gave to the base of the channel, is it heat flux or temperature?
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Old   October 30, 2012, 01:38
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Hi
Is your geometry 2D or 3D
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Old   October 30, 2012, 01:40
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Quote:
Originally Posted by sofie1 View Post
Hi
Is your geometry 2D or 3D
Thanks for reply ......

my geometry is 3D
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Old   October 30, 2012, 01:41
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Quote:
Originally Posted by A7A View Post
Hi,

What is the type of BC you gave to the base of the channel, is it heat flux or temperature?
thanks for reply .......

heat flux
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Old   October 30, 2012, 10:30
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As the BC is heat flux, fluent will give you this result(constant heat flux), and if you want to check how the heat flux is changing along the channel base you have to use temperature as BC for the channel base.
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Old   October 30, 2012, 10:32
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Quote:
Originally Posted by A7A View Post
As the BC is heat flux, fluent will give you this result(constant heat flux), and if you want to check how the heat flux is changing along the channel base you have to use temperature as BC for the channel base.
but why there is jump in the end and the bedninig ??
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Old   October 30, 2012, 10:42
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I dont know why fluent give this jump, but have you checked the temperature variation along the channel base, and the heat transfer coefficient. If there isnt any thing wrong so it maybe something related to the nature of the mesh you are using.
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Old   October 30, 2012, 10:46
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Quote:
Originally Posted by A7A View Post
I dont know why fluent give this jump, but have you checked the temperature variation along the channel base, and the heat transfer coefficient. If there isnt any thing wrong so it maybe something related to the nature of the mesh you are using.
the Tem distribution is ok but the Nu number dont go to standard ( 4.3 ) , Nu go to zero ??
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Old   October 30, 2012, 10:49
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could you put a picture of temperature and Nu plots.
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Old   October 30, 2012, 12:34
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Quote:
Originally Posted by A7A View Post
could you put a picture of temperature and Nu plots.
i attached the pictures
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Old   November 3, 2012, 04:52
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The temperature of the channel base is decreasing, so Nu number must be increasing along the channel base, but Nu plot doesnt give you this result because of the jump of Nu number at the end of channel, so try to decrease the range of the Y-axis of the plot to see what is the real distribution of Nu number.
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Old   November 5, 2012, 12:21
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Quote:
Originally Posted by A7A View Post
The temperature of the channel base is decreasing, so Nu number must be increasing along the channel base, but Nu plot doesnt give you this result because of the jump of Nu number at the end of channel, so try to decrease the range of the Y-axis of the plot to see what is the real distribution of Nu number.
thanks for reply ...
what about Nu no didnt go to 4.32
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Old   November 7, 2012, 12:19
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Have you checked the reference values you are using like length and temperature.
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Old   November 7, 2012, 12:21
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Quote:
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Have you checked the reference values you are using like length and temperature.
yes i have checked it ...also i try to change it but still no way ..
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Old   March 7, 2013, 01:52
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Malay, did you solve your problem with the heat transfer spikes at each end? I am having similar issues. Could it be a problem in the mesh?
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Old   March 7, 2013, 03:06
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Malay, did you solve your problem with the heat transfer spikes at each end? I am having similar issues. Could it be a problem in the mesh?
not yet ... do you have any idea ?
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Old   March 14, 2013, 23:11
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Malay,

Do you have a constant temperature value set for your inlet total temperature? If so, this may be a problem. For my inlet conditions, I imported a total temperature profile simulating a thermal boundary layer and this fixed the heat transfer spike at the inlet.

Best of luck!
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Old   March 15, 2013, 03:13
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Try to untick the "node values" option for your plot.
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