# FLUENT - EVAPORATION and CONDENSATION SIMULATION

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 June 21, 2010, 08:44 FLUENT - EVAPORATION and CONDENSATION SIMULATION #1 New Member   Patryk Join Date: Mar 2009 Posts: 4 Rep Power: 17 Let's say there is a closed aluminum cube. The cube is filled in 1/5 with water and in 4/5 with air . 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 chaitanyaarige and Ahmed Alkaisi like this.

 April 24, 2014, 23:43 #2 New Member   Xiaobing Zhang Join Date: Apr 2014 Posts: 12 Rep Power: 12 Hi I'm doing similar modeling, can u tell me how did you do this simulation in the end?: Thanks

 April 25, 2014, 01:35 #3 New Member   Junphy Liues Join Date: Apr 2014 Posts: 9 Rep Power: 12 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. chaitanyaarige and xiaobingwill like this.

April 30, 2014, 00:38
#4
New Member

Xiaobing Zhang
Join Date: Apr 2014
Posts: 12
Rep Power: 12
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 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.

 April 30, 2014, 02:29 #5 New Member   Arun Tamilarasan Join Date: Apr 2014 Posts: 3 Rep Power: 12 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. chaitanyaarige likes this.

May 14, 2014, 09:54
droplet evaporation
#6
New Member

navid
Join Date: May 2012
Posts: 6
Rep Power: 13
Quote:
 Originally Posted by arunt 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.

 May 14, 2014, 11:07 #7 Senior Member   Behrooz Jamshidi Join Date: Apr 2013 Posts: 110 Rep Power: 13 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.

 August 23, 2014, 21:14 #8 Senior Member   Bill Wang Join Date: Aug 2014 Posts: 109 Rep Power: 11 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

February 20, 2016, 02:26
#9
Member

Nazim
Join Date: Oct 2013
Posts: 93
Rep Power: 12
Quote:
 Originally Posted by 6863523 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

February 20, 2016, 02:27
#10
Member

Nazim
Join Date: Oct 2013
Posts: 93
Rep Power: 12
Quote:
 Originally Posted by xiaobingwill 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

February 20, 2016, 02:28
#11
Member

Nazim
Join Date: Oct 2013
Posts: 93
Rep Power: 12
Quote:
 Originally Posted by Ahmed Alkaisi 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 Many thanks all Yours, Alkaisi ahmedalkaisi82@gmail.com
VOF OFfcourse

 June 12, 2017, 14:22 #12 Member     ram Join Date: Apr 2013 Posts: 37 Rep Power: 13 VOF is not suitable when phases are interpenetrating. Is is better to use it when boundary between phases is sharp as like open channels (water - air) As far as in know, older versions of Fluent dont have phase change icon. it is better to use Ansys Fluent versions.

 July 4, 2017, 01:51 #13 Member     Ahmed Alkaisi Join Date: Aug 2015 Location: Australia Posts: 80 Rep Power: 10 Hi all Firstly, from my experience vof model is the best and the easiest way to deal with evaporation- condensation multiphase problem. Secondly, do you have any update on your simulation? Regards Sent from my SM-G900I using CFD Online Forum mobile app

September 25, 2018, 14:17
#14
New Member

Tonoy Mondol
Join Date: Sep 2018
Posts: 13
Rep Power: 7
Quote:
 Originally Posted by Patryk Let's say there is a closed aluminum cube. The cube is filled in 1/5 with water and in 4/5 with air . 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
have you done the problem? I want your code for an idea related to evaporation condensation

January 15, 2019, 06:50
#15
New Member

GW
Join Date: Nov 2018
Posts: 6
Rep Power: 7
Quote:
 Originally Posted by Tonoy Mondol have you done the problem? I want your code for an idea related to evaporation condensation
The problem I am facing now is that after adding UDF, the gas phase will not increase. Do you solve it? Could you share your code? 603570326@qq.com

March 12, 2019, 08:09
#16
New Member

jeet verma
Join Date: Mar 2019
Posts: 4
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Quote:
 Originally Posted by violin000 The problem I am facing now is that after adding UDF, the gas phase will not increase. Do you solve it? Could you share your code? 603570326@qq.com
i am also facing the sane type of problem can you please send me your code at jeet.vrm18@gmail.com

 June 20, 2019, 20:28 #17 Member   Soumitra Vadnerkar Join Date: Aug 2018 Posts: 70 Rep Power: 7 I am using evaporation-condensation model. I also tried the Mass rate Linearization UDF available in Fluent UDF guide. But I am not able to see the considerable liquid vapor fraction. My case is tube flow inlet at 240C @ 3 MPa water vapor. Tube wall is isothermal @100C. At exit pressure drop is 7.25KPa (experiment) with complete condensation to liquid phase. I am getting the pressure drop right, but temperature profile significantly lower than the experimental. Can somebody suggest me something on this. my email is soumitra2102@gmil.com Thank You.

 September 27, 2020, 09:22 #18 New Member   Aman Jaiswal Join Date: Sep 2020 Posts: 3 Rep Power: 5 hello sir, can you please help me simulating a single water droplet evaporation in static air surrounding. my mail : aman.mec1721@yahoo.com

September 27, 2020, 09:23
#19
New Member

Aman Jaiswal
Join Date: Sep 2020
Posts: 3
Rep Power: 5
Quote:
 Originally Posted by Ahmed Alkaisi Hi all Firstly, from my experience vof model is the best and the easiest way to deal with evaporation- condensation multiphase problem. Secondly, do you have any update on your simulation? Regards Sent from my SM-G900I using CFD Online Forum mobile app
hello sir, can you please help me simulating a single water droplet evaporation in static air surrounding.
my mail : aman.mec1721@yahoo.com

 Tags evaporation condensation