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How to transform (mass flow rate) boundary condition from 3D to 2D? 

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October 18, 2012, 03:26 
How to transform (mass flow rate) boundary condition from 3D to 2D?

#1 
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Nurul
Join Date: Sep 2012
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Hello everybody,
I'm using CFDFluent to simulate gasification. In my case, mass flow rate that enter gasifier column is 0,0074 kg/s of coal. I want to simulate with 2D geometry. Only half of the domain with is modeled because of symmetry. Is it same the number of mass flow rate in 3D and 2D? Is the mass flow rate used in 2D unchanged (0,0074 kg/s)? Or the mass flow rate must be devided to transform in 2D? I hope you can help me. Thanks. Last edited by nurul efha; October 18, 2012 at 04:09. 

October 20, 2012, 13:29 

#2 
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Hi.
Are you using 2D Axsymmetric? If yes, mass flow should be divided by (2*PI). You are just modeling 1 rad of the whole circle.
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Saeed Sadeghi Ansys Fluent CFD Consultant 

October 21, 2012, 17:59 

#3  
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misagh
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Quote:
You had better use intensive property for your simulation and further calculation.it is an easy way to get rid of changing units in 2.d or 3.d . i mean instead of using mass flow rate(which is an extensive property) just use velocity(intensive property) good luck 

October 21, 2012, 20:47 

#4 
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Nurul
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October 21, 2012, 20:49 

#5  
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Nurul
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Quote:
I think so. Thanks... 

October 27, 2012, 14:03 

#6  
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Nick
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Quote:
Can you expand on this ? I have always entered the full mass flow for axisymetric problems, not a 1 rad slice... Quick search to find a Fluent manual online, reveals the following, (v6.3) http://hpce.iitm.ac.in/website/Manua...ug/node227.htm Quote:


July 31, 2016, 19:11 

#7  
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John
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Quote:
"Note that for axisymmetric problems, this mass flow rate is the flow rate through the entire ( $2\pi$radian) domain, not through a 1radian slice." https://www.sharcnet.ca/Software/Ans...low_Inlet.html Only Mass Flux is through the 1radian slice: "mass flux is the flux through a 1radian slice of the domain." 

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