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saidkhaled March 28, 2020 08:46
Fluent Custom Field function
 
1 Attachment(s)
Dear all,
I hope all of u are doing well ,
I am solving natural convection inside heated cavity and i would like to calculate some quantities using custom field function. However as may be seen below the results are wrong and unfortunately this is the case for all mathematical operations. my question is do u have guys an idea how to solve this problem. thank you so muchAttachment 75980

vinerm March 28, 2020 15:20
Volume Average
 
The reason for that is volume averaging. If all the cells in your mesh are of exactly same volume, then answer would be what you expect, i.e., 90000. However, that is certainly not the case. Volume averaged temperature is defined as

\frac{\sum T_{cell} \times V_{cell}}{\sum V_{cell}}

vinerm March 30, 2020 06:16
Exact Solution
 
The solution is to report out the temperature values for the cell. Go to File > Export > Solution data and then report temperature values for all cells in a text file. Then you can load this file in a text editor, such as vi or textpad to look at how much variation is there in temperature values.


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