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-   -   FLUENT - EVAPORATION and CONDENSATION SIMULATION (http://www.cfd-online.com/Forums/fluent/77357-fluent-evaporation-condensation-simulation.html)

Patryk June 21, 2010 08:44

FLUENT - EVAPORATION and CONDENSATION SIMULATION
 
Let's say there is a closed aluminum cube. The cube is filled in 1/5 with water and in 4/5 with air :eek:. The deck of the cube is a source of the heat. The surface of the cube is constantly cooled. The water in it evaporates, traveles to the surface, gets cooled, condensates and drops down (some kind of a heat pipe).
I want to simulate it with FLUENT.

Questions:
Which model of phases is appropriate(VOF,Eulerian,DPM,Mixture model)? How manage with mass transfer from liquid phase to gasous and vice versa? How simulate heat transfer in this case?
Thank you in advance,
Patryk

xiaobingwill April 24, 2014 23:43

Hi I'm doing similar modeling, can u tell me how did you do this simulation in the end?: Thanks

Junphy April 25, 2014 01:35

I am working on this simulation right now, mixture is perfect I think, the result is better than other models. U need to wright some UDFs to realize the phase change.

xiaobingwill April 30, 2014 00:38

Hi Junphy,

Is it OK for you to share your UDF with me? I got stuck with condensation, and my results with evaporation is not that good. Can you please help me with this?

My email is zhangxiaobinghust@gmail.com

Thanks a lot!

Quote:

Originally Posted by Junphy (Post 488101)
I am working on this simulation right now, mixture is perfect I think, the result is better than other models. U need to wright some UDFs to realize the phase change.


arunt April 30, 2014 02:29

Hey,
I am working on a similar problem but I am focusing on the evaporation behavior alone. The mixture model seems to work fine and as for the UDF, if you have the fluent UDF manual, you can refer it and get on it on your own. Also, you will have to patch water and vapor regions at t=0. For some reason, I cannot patch them and the vapor volume fraction seems zero always. Anyway, the mixture model will be the correct multiphase physics for your problem.

Arun.

navid2 May 14, 2014 09:54

droplet evaporation
 
Quote:

Originally Posted by arunt (Post 489052)
Hey,
I am working on a similar problem but I am focusing on the evaporation behavior alone. The mixture model seems to work fine and as for the UDF, if you have the fluent UDF manual, you can refer it and get on it on your own. Also, you will have to patch water and vapor regions at t=0. For some reason, I cannot patch them and the vapor volume fraction seems zero always. Anyway, the mixture model will be the correct multiphase physics for your problem.

Arun.

hi
i'm working on evaporation of a single water droplet in a square computational field that is included static air. can u help me about settings of ansys fluent for this problem?
any helps is appreciated.

CFD-fellow May 14, 2014 11:07

Hi
With AnsysFluent its not needed to write udf.It has the mass transfer equations for evaporation and condensation.
These kinds of simulations are really hard to be handled by commercial codes.

6863523 August 23, 2014 21:14

Hi CFD-fellow,
I tried the evaporation and condensation mechanism of transient VOF model in FLUENT14.5, but the result is not good, as the phase fraction always change with time and in the final, either the liquid turned in to vapor or vapor turned into liquid. the problem is in the vapor domain, liquid shoud not exist vise verse. I did not interpret/compile any UDFs. At the initial of the simulation, I patched liquid in liquid domain and vapor in vapor domain.
Have you worked the simulation out? Would you please give me some hint? email:1612955572@qq.com
Thank you in advance.
Regards,
Bill

shahid nadeem February 20, 2016 03:26

Quote:

Originally Posted by 6863523 (Post 507489)
Hi CFD-fellow,
I tried the evaporation and condensation mechanism of transient VOF model in FLUENT14.5, but the result is not good, as the phase fraction always change with time and in the final, either the liquid turned in to vapor or vapor turned into liquid. the problem is in the vapor domain, liquid shoud not exist vise verse. I did not interpret/compile any UDFs. At the initial of the simulation, I patched liquid in liquid domain and vapor in vapor domain.
Have you worked the simulation out? Would you please give me some hint? email:1612955572@qq.com
Thank you in advance.
Regards,
Bill

Dear did you got the results kindly share the steps with me

shahid nadeem February 20, 2016 03:27

Quote:

Originally Posted by xiaobingwill (Post 489041)
Hi Junphy,

Is it OK for you to share your UDF with me? I got stuck with condensation, and my results with evaporation is not that good. Can you please help me with this?

My email is zhangxiaobinghust@gmail.com

Thanks a lot!

Hello did you got the UDF and if yes kindly share with me at snadeembe@gmail.com

shahid nadeem February 20, 2016 03:28

Quote:

Originally Posted by Ahmed Alkaisi (Post 585811)
Hi all,
* Can anyone tell me which model will be perfect for water evaporation-condensation in a close or open system within Fluent environment, please?
* Is it VOF, Eulerian or Mixture Model? and
* How many phases should I chose 2 ( water and air)
or 3 ( water, air and mixture)?
Answer me please:D
Many thanks all
Yours, Alkaisi:)
ahmedalkaisi82@gmail.com

VOF OFfcourse


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