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

Evaporation UDF

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 8, 2003, 21:37
Default Evaporation UDF
  #1
MN
Guest
 
Posts: n/a
I've been looking around here and on the net but haven't found anything good yet.

I've got a hot flow of gas flowing upwards in a pipe, past a small arm where a slow rate of a cold, volatile liquid is being pumped into the large pipe. Geometry is all nicely Hex/Cooper'd. At the conditions of this system, the end state should be the complete evaporation of the liquid into the gas phase, but of course I'd like to know what's happening at a local scale. There's no (effective) interaction between the liquid substance and the hot gas phase beyond mixing, but there is some heat loss due to the latent heat supplied by the hot gas.

I've set up a basic steady-state model using a Mixture multiphase system, with 3 phases: the hot gas, the liquid, and the gas phase of the system. I can do the liquid into the hot gas alone with no problem, but I'm attempting to add the vaporized liquid phase and finding problems with the evaporation model. I know the UDF manual has an example mass transfer (and thus energy transfer) between the two phases, but this seems to assume there's an infinite amount of the liquid phase, AND that there's no upper bound to the saturation of the vapor phase. I've been looking around on the net for something else that I could use, but haven't found anything that seems to meet the needs I have.

I know I could possibly use a DPM, assuming liquid droplets that enter the gas stream, but this would not seem as realistic for the situation based on what I already know.

Has anyone written a general UDF for such a situation or have pointers to information where such a UDF could be generated, or have other suggestions for approaching this problem?
  Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to simulate the process of water evaporation by UDF? qiyang860908 Fluent UDF and Scheme Programming 10 January 9, 2015 14:59
how to write udf for evaporation in heat pipe???? Anbazhagan R Fluent UDF and Scheme Programming 2 May 3, 2009 08:43
UDF for water evaporation syed FLUENT 0 March 14, 2007 23:21
UDF water evaporation emanuele FLUENT 0 March 12, 2007 17:34
UDF for evaporation Shanti FLUENT 0 March 8, 2006 19:49


All times are GMT -4. The time now is 23:22.