boiling and condensation
 

hi all i am solving one heat pipe prolem includes condensation and boiling(phase change model).i want to know that which model is better and can i solve without udf.

advance thanks

Re: boiling and condensation
 

Hi brusly,

There is a tutorial on boiling.please have a look at it.

www.fluentusers.com

I think you can discrete phase model for this but you would be required to use an UDF to simulate the condensation since it is not automatically done in fluent.

All the best.

Regards

Rajit

Re: boiling and condensation
 

thanks ranjit

Re: boiling and condensation
 

i am not able to get the tuitorials.plz anyone having the tutorial.

advance thanks

Re: boiling and condensation
 

Hi Brusly,

Please forward me your personal mail id. I will post the tutorial for you.

Thanks

Rajit

Re: boiling and condensation
 

if there is a free surface in heat pipe (is there) why not use a VOF model??

Re: boiling and condensation
 

Hello, Rajit

I am working on two phase flow with phase change,also.Please ,If it is possible for you send me toturial file.My email address is : saimon_ph@yahoo.com

Thanks in advance.

Re: to ranjit
 

hai ranjit this is brusly my id is brusly_solomon@yahoo.co.in thanks a lot

Re: boiling and condensation
 

hi rajit, im also working on chill down problem (2 phase flow) can u send me the tutorials, my email id is ravindra.emani@gmail.com thanks in advance. bye

Re: boiling and condensation
 

hi greg

i have model a circular pipe,outer surface were divided in to 3 surfaces evoporator,adiabatic section,condensor like wise ,inside in the evoporator section boiling takeplace and in the condensor part codensation will be takeplace

ia it possible with vof

thank u

Re: boiling and condensation
 

Hi,rajit;

Thank you very much for sending tutorial files, but i have a question from you:

Is this udf used for evaporation and condensation,synchronously ?

Thanks for your response;

Asghari

Re: boiling and condensation
 

hi In my opinion one toutorial can be use for boiling and condensation and evaporation. Everything depends of temperature. You can set up an equation (or if else statement) that evapoarion can take place below boiling point and evapoarion over it. The Define_mass_transfer is so kind of macro that you can define from which phase to which phase mass transfer can be. Boiling from liquid to gas and condensation from gas to liquid. I never done a condensation but I think it is possible. Please let me know if I`m wrong. good luck

Re: boiling and condensation
 

thank u i will try it

Re: boiling and condensation
 

hi I have on probblem with this boiling. using standard (provided by Fluent) tutorials - means udf`s I can get boiling of water (both in VOF and Mixture model) but.... the temperatures are stupid. In liquid pase temperature is OK but in gas phase it reach maximum or minimum temperature (1K or 5000K which are max and min. temperatures in FLUENT). Do yuo happen to know what to do? Meybe you had the same problem. regards g

Re: boiling and condensation
 

hej Greg! This problem with Temp. min or max in Fluent, is normal, You must change value in equation, on conference I listen aboaut this problem

Re: boiling and condensation
 

oooo You made me to belive it can be solved. :)

"You must change value in equation, on conference I listen aboaut this problem "

In my equation (put by me inside the udf)?? When I will change the value in my equation than I will change the results (isn`t it??). You mean value in which equation? In UDF there isn`t many values: relaxation time (0,1s - constant) and the rest of the values are values like temperature, density or volume. can you provide me more clues. Thank you for hope :))))

Re: boiling and condensation
 

Misiu are you from Poland?? Meybe you have any papers (descrabing my problem) from this conference you are talking aboute and you are able to send it to me?

Greg

Re: boiling and condensation
 

Yeea I`m from Polska (Poland) Technology University I haven`t any information about "this" problem, only to hear about min and max temperature in proccessing boiling in Fluent. Perhaps You must change boundary steady or unsteady condition Best regards

Re: boiling and condensation
 

ok I will try. Misiek sounds fimiliar for me so I asked. Something like teddy bear

Re: boiling and condensation
 

Rajit, Would u plz email the tutorial to me. I have also the same problem with boiling.

Mohammad My email address is mhfd39 @ Y!

Please Help
 

Hello

Please email the tutorial to me as well.
It will be a great help.
Email ID computational.fluids@gmail.com

God Bless you all
Techy

hi

I am also having same problem while doing condensation simulation. please forward the tutorial to my mail also. it would be a great help. my email id: d.madan7@gmail.com

regards

I'd also appreciate it if someone could send me the water boiling tutorials.

I am trying to learn CFD for a university project, but can't access the tutorials via the university since they are not installed on the work computers and do not know who to contact.

My email is: c.j.laumans@student.tudelft.nl

Thanks a lot,

Chris

Hi Rajit
Can you send me tutorial file which is on condensation and boiling my email id is mahesh.dhaigude6@gmail.com

Does anyone still have this tutorial? If you do, could you send it to my email: Michael_Eskowitz@yahoo.com

Thanks a ton.

-Mike

--
 

Rajit please kindly send to me the tutorial file on evaporation and condensation as well. My email id is weihow_8@hotmail.com
THX in advance yA!! ur help is much appriciated.

Hello, is this tutorial still there in www.fluentusers.com, I can't find it. Could someone sent me the Link to this tutorial.
Thank you.

Hi every body,

I'm using VOF to model two-Phase flow in a heat pipe. Here is my questions:

FLUENT\Phases\Interactions\Mass

1- Am I supposed to define more than one mechanisms? one for <from phase 1 to 2> and another one <from phase 2 to 1>

2- My FLUENT has a another option you guys never talked about <evaporation-condensation> mechanism which has a Edit option to define a criterion based on both Temperature and Pressure. Anyway, my question is that, after clicking Edit button, it'd ask you about Evaporation and Condensation Frequency. What's that?

FYI:
http://mehdifamouri.persiangig.com/untitled.JPG

Thanks in Advance,

hi mehdi,

the equiations behind the settings are well described in the theory guide at the chapter 17.7.5 evaporation and condensation

Thanks for your help. I'm a beginner and I'd really appreciate it if you could send me a link to get that Theory Guide.

here is the link to the 12 th theory guide version
http://www1.ansys.com/customer/conte...luent/flth.pdf

Thanks for your help, I really appreciate your time. But, through the link you sent me, I found the user guide and chapter 17.7 was about Species Equations (Page 645/816)and there were no 17.7.5. However, I couldn't get any idea about my former questions from this part (17.7 Species Equations). I'd really appreciate it if you could look through the link you send me to make sure it's the very link you were talking about.

Thanks in Advance,

sorry my mistake,
give me your e-mail, I will give you what you are searching for!

Here is my e-mail: famoor62@yahoo.com
Many Thanks,

udf usage & boiling-condensation...
 

Hi ranjit,

Could u guide me to do modeling of evaparative tubes in boiler... I want to do simulation and know the effects...?

Could you please do forward the tutorial on Gambit and fluent usage - boiling and condensation. As i am new to it... and not able to access fluentusers...

I am new to udf too... give some tips to start using udf, where i can use and purpose of udf....

chandrasekhar.gullapalli@gmail.com

Thanks in advance...

chandu.

Hi
Would you send me the tutorial file too.
Thank you.
my email: mohammad_km2006@yahoo.com

Hi Rajit
would you plz send me the boiling tutorial on my mail: hamdy.abotaleb@yahoo.com

Thanks

Hi Rajit,
If you have this tutorial or any UDF about heat pipe, please send me also:
masoud734@tahoo.com

hi boy
can any one send me(mesh file+c.file) of tutorial horizontal film boiling plz

saeed0913@yahoo.com

How can i modeled two phase for two fluid in fluent?
 

I try to do fluent simulation for condenser of power plant
this condenser uses a cooling fluid to condense the steam to saturated liquid and the cooling fluid gained this heat to evaporate.
So, the cooling fluid is two phase converts from liquid to vapor ( it inlets as liquid and gains heat to become vapor. in the other side the steam loss its heat to cooling fluid to become saturated liquid.there is copper wall between them to act the heat transfer wall.
If anyone can help??????????????