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August 13, 2011, 08:12 |
modeling condensation in humid air...
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#1 |
New Member
Alireza Mashayekh
Join Date: Aug 2011
Posts: 3
Rep Power: 15 |
Hi everybody;
I am working on a project in which I have to consider condensation in humid air. it is a cross-flow condenser, which it's use is in air conditioning; in it's hot air inlet, the air is mixed with some water vapor, and the other side is cold air. in this process I have to capture the phase change from water-vapor, to water-liquid. can anyone plz help me in this?! which multiphase model is proper for this simulation?! may I use the mixture model, or it won't include phase changes?! if I should use species to model this project, does anyone know the coefficients that I have to use for condensation (latent heat modelling) and properties that I should set?! tnx in advance for your helps... |
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September 22, 2011, 12:26 |
condensation
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#2 | |
Senior Member
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Hi,
use either a two-fluid or even a mixture model - doesnt matter. You need to write appropriate mass transfer function. Not only volumetric condensation - you probably have to model wall condensation as well. which code are you using to perform these calculations? Good luck, CFDtoy Quote:
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CFDtoy |
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September 22, 2011, 13:17 |
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#3 |
New Member
Alireza Mashayekh
Join Date: Aug 2011
Posts: 3
Rep Power: 15 |
Hi CFDtoy; tnx for ur answer...
I'm using ANSYS 13.0 which seems that have the mass transfer functions embedded in its own models! but the problem is that when I use it, even for the most simple geometries, it won't converge!!! (the equation which this mass transfer function uses is "ranz-marshall") I've tried it with several different models like, Eulerian and mixture and I've tried each one with different inlet types, different magnitudes for inlets and etc. I just don't know which option I'm using wrong that makes it diverge!!! so I would be more thankful if you could help me out here... |
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September 29, 2011, 12:56 |
convergence issue
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#4 | |
Senior Member
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Hi,
I dont have the recent ANSYS 13 manual - so dont know what input is being specified from your end. Is it possible for you to upload / send ANSYS manual for this feature alone? I think the settings in the model can clearly help you out here. I have experience in boiling models both coding and usage (commercial) - convergence can purely be manipulated by the implemented model. Thanks, CFDtoy Quote:
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CFDtoy |
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September 29, 2011, 15:11 |
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#5 |
New Member
Alireza Mashayekh
Join Date: Aug 2011
Posts: 3
Rep Power: 15 |
Hi again, and thank for your patience;
as this new version of ansys has a help in java format, I couldn't get a print out of it to send to you; but I got some screen pictures of the settings I set: 1. this picture shows my "Models" tab: 2. this pic is my settings on Eulerian mode: 3. these are my materials: 4. my phases definition: 5. "phase interaction" window: 6. settings on heat transfer method for this feature: 7. and finally the mass transfer model settings: I hope that these pictures can help both of us! thanks again; I'm waiting to hear from you... |
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July 30, 2012, 12:40 |
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#6 |
New Member
Mike
Join Date: Jun 2012
Location: Wooster, OH
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Rep Power: 14 |
I know this thread is a bit old, but did you try changing the "from" and "to" phases in your evaporation-condensation model settings? I am trying to model condensation in my own simulation, and the evaporation-condensation only works for me when it's going from liquid to gas (condensation would then be a negative mass transfer).
-Mike |
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August 21, 2014, 04:03 |
Similar Condensation problem
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#7 |
New Member
Sathya Narayanan
Join Date: Apr 2014
Posts: 18
Rep Power: 12 |
Hi ,
I've been trying to solve a similar condensation case. Can I do it without a UDF in Fluent 14 ? I activated the mass transfer model to " Evaporation-Condensation". But when i plot the Volume fraction i do not find proper phase change. |
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August 29, 2014, 03:56 |
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#8 |
New Member
Kağan Peneklioğlu
Join Date: Oct 2013
Posts: 2
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This is the what i have meet before and i cant fixed it. What should i do ? Does anyone has any idea ?
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August 29, 2014, 18:04 |
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#9 | |
Senior Member
Ehsan Asgari
Join Date: Apr 2010
Posts: 473
Rep Power: 18 |
Quote:
Bests |
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May 7, 2015, 20:12 |
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#10 |
New Member
anonymous
Join Date: Jan 2015
Posts: 3
Rep Power: 11 |
hii
and finally did you find a solution for your problem ? |
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Tags |
condensation, multiphase, phase change |
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