CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

Evaporation

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   February 20, 2006, 20:07
Default Evaporation
  #1
Shanti
Guest
 
Posts: n/a
Hi

I am modelling a two-phase system. One of the phases has 2 species. One of the species is evaporating into the other phase(ie air). I have included mixture model and species transport model. Does this take into consideration, that the liquid phase is being converted into a gaseous phase, or do i need to define a UDF for it?

Please help me..

Thanks
  Reply With Quote

Old   February 21, 2006, 00:08
Default Re: Evaporation
  #2
turbomachinery
Guest
 
Posts: n/a
yes, there is a tuturial case in FLUENT about water boiling and there is a UDF using in simulating this question.
  Reply With Quote

Old   February 21, 2006, 04:40
Default Re: Evaporation
  #3
MANOJKUMAR
Guest
 
Posts: n/a
Hi, I setting the injection in my problem but there is not evaporated it say incompleted. what tempereture to given for the evaporation.
  Reply With Quote

Old   February 21, 2006, 14:10
Default Re: Evaporation
  #4
James
Guest
 
Posts: n/a
Hi,

what is your boiling point temp. and what about your partial vapor pressure? This is very important and it is good to have it set to piecewise polynomial. It affects to a great extent the evaporation process and also the boiling point temp. should be very accurate.

Any idea what your operating pressure is? The boiling point temp. also varies with the operating pressure.

If you are not having any evaporation, then i suggest as a first step to check these properties.

Also, what boundary conditions did you use for the droplets at the walls? Maybe most of your droplets are hitting the wall and so this boundary condition is important. The trap condition is the most ideal. With this, when a droplet hits a wall, it is trap and it completely evaporates and the liquid fuel evaporated is added to the gaseous phase. Fluent doesn't take the energy needed for this process from the flow and so your enthalpy balance is not affected.

James

  Reply With Quote

Old   February 22, 2006, 05:52
Default Re: Evaporation
  #5
MANOJKUMAR
Guest
 
Posts: n/a
THANKS JAMES CAN U GIVE UR E-MAIL ID MY E-AMIL IS ms_project05@rediffmail.com
  Reply With Quote

Old   July 12, 2014, 04:59
Default
  #6
New Member
 
kohl
Join Date: Feb 2013
Posts: 7
Rep Power: 4
ilphma is on a distinguished road
i'm using fluent for simulating an injection. because of the hot airstream, the droplets reach the boiling point very fast and there is no chance for most of them to evaporate with law2. but when they reach to boiling point, as said in user guide, they just stay in boiling point and in this case there is no new evaporating!

how can i fix that problem? how they can continue evaporating after reaching the boiling point temperature?
ilphma is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Evaporation model in ansys Fluent 12.1 oldisbest Fluent UDF and Scheme Programming 9 June 13, 2013 22:44
Evaporation due to Heat Transport using InterFoam (Correct Implementation?) ovie OpenFOAM 12 December 16, 2011 10:44
Question:Considerations about the evaporation in VOF dokeun FLUENT 10 February 24, 2011 21:47
CFX Liquid Evaporation Model Jinx CFX 3 January 28, 2010 17:31
Defining Evaporation - A How To Guide. Owen FLUENT 1 July 25, 2005 09:56


All times are GMT -4. The time now is 17:24.