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September 18, 2015, 06:43 
Estimating Tmean in CFD post

#1 
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Hello I attempt to estimate Tm using CFD post which defined as illustrated at the image may somebody guide me how can I write this expression in CFD post?
mariam 

September 18, 2015, 07:58 

#2 
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Your expression already assumes constant/uniform specific heat capacity, Cp. Therefore, you can use the standard CEL averaging functions.
Since Cp cancels out, T_mean = massFlowAve(Temperature)@Locator The next step is to define the Locator of interest. Perhaps you define a cut plane through the geometry, and use it to evaluate the expression. 

September 18, 2015, 08:19 

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Hello I draw a line through the geometry named it as Line 1 at section where x=0.7125 m from pipe inlet and wrote an expression as:
Tm=massFlowAve(Temperature)@Line 1 but when I press evaluate it give me the error below: Error Only geometries with surface data are allowed for calculating massFlowAve what the problem??????? 

September 18, 2015, 08:38 

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The message is very clear.. You want to evaluate an area integral on a line ? There is no cross section, or any area.


September 18, 2015, 08:45 

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So what I can do to evaluate Tm along this line ? No idea else?


September 18, 2015, 09:00 

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I think you need to better describe what you are trying to achieve.
The mean, ( or better known bulk) temperature is defined for a cross section of the flow and nothing else. What is your cross section of interest ? Perhaps you intend to plot the variation of the bulk temperature along a series of cross sections that follow some kind of line path. To start, I would do the manual work. Create the cross section of interest, evaluate T_mean, create another one downstream, evaluate and confirm you are in the right direction. Then, you try to automate, simplify the effort. 

September 18, 2015, 09:05 

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Actually I am trying to evaluate Tm in order to estimate heat transfer coefficient from the relation:
h=heat flux/(TwallTbulk) I have 2 D pipe geometry and want predict h at different axial locations I used Fluent for simulations just use CFD post for results 

September 18, 2015, 09:56 

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Quote:


September 18, 2015, 10:45 

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September 18, 2015, 12:41 

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September 18, 2015, 14:20 

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September 18, 2015, 15:25 

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September 19, 2015, 08:10 

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September 19, 2015, 12:42 

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