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January 3, 2008, 05:00 
Diffference between mass weighted average and Area

#1 
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Hi, I don't understand the difference between Mass weighted average and area weighted average, when i must use one or the other. (results are very different).
Thanks 

January 8, 2008, 13:19 
Re: Diffference between mass weighted average and

#2 
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Mass averaging is summation of (value * mass flow) / summation of mass flow over the surface of interest. Area averaging is summation of (value * area) / summation of area over the surface of interest.


September 24, 2012, 13:13 
regarding mass weighted average velocity

#3 
New Member
abhi
Join Date: Sep 2012
Posts: 11
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Hi,
i just want to know that is average velocity( mass weighted ) dependent on grid number ? Actually i am simulating flow through pipe , and flow is laminar so friction factor theoretical is 64/ Re . And flow is fully developed(done using C coding) .for Re 500 f th is 0.128. and i am getting 0.145 and its not acceptable i guess. U max is 0.01817. So actual avg. velocity value should be 0.01284813 but fluent giving me d value 0.012135. Can anyone tell me whats going wrong or how to improve avg. velocity value (mass weighted ) Since flow is laminar we cant get actual pressure drop(static) and its coming out 0.2396 and fluent giving me 0.24 so its close only problem is with velocity plz. tell what is wrong 

September 24, 2012, 16:42 

#4  
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Syavash
Join Date: Apr 2010
Location: Tehran, Karaj
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Quote:


September 25, 2012, 01:36 

#5 
New Member
abhi
Join Date: Sep 2012
Posts: 11
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I tried with 0.1 million cell count and 0.6 million, only i could see decrease in pressure drop but average velocity remained same


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