Hello everyone!

I am doing a project that will require an emulation of water evaporation and condesation in a enclosed glass box structure (measures 4x20 meters) with a thin layer of water (0.3-0.6 meters deep)laying at the bottom of the container. Physicaly, the water will start to evaporate when the sun hits the water and raises the tempature, while the evaporated water vapour (gas) rises to the ceiling and subseqently condensate into liquid water when reaches dew point. The question is if the measurements of the glass box and the volumn of the thin layer of water and the air temperature outside the box is given, how can i model the evporation and condensation process and phenomenon? (either in CFX or Fluent) Since I am a total beginner, please be simple and step by step if possible, or if there is any example or tutorials exist somewhere, please let me know!!

thanks a million!

Linjie

first. If you want to use a 3D model you need to do a 3D model of your domain but if you doesn`t want to do 3D calculations 2 D model is OK. Statement above is very important if you want to model solar radiation (and use solar ray tracing model) - it is imposible in 2D. In 2D you have to assume bottom surface of tank (glass box) as an heating source with ttmperature or heat flux BC or apper wall as an heat source and use some radiation model (I wouldn`t do that becausee you want to have a condenastation at the top of tank). Than you have to create 2 phases and use appropriate UDF for this 2 phenomona. Please read tutorial about VOF model and FILM BOILING and BOIL tutorial. You can find it on www.fluentusers.com and some manual aboute UDF.

good luck

Thanks very much for the advice, I will look into it!! Cheers!

Linjie

[vaibhavraikhare]

Hello Linjie
i am working on same as your project was.plz guide me on it..i m using fluent 6.3. mixture model, PBM model for mass transfer of liq, DTRM for solar radiation with solar ray tracing...is it correct bcoz m nt getting results.
plz help..
thnkx