CFD Online Logo CFD Online URL
Home > Forums > FLUENT

natural ventilation

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

LinkBack Thread Tools Display Modes
Old   June 8, 2011, 04:30
Default natural ventilation
New Member
Join Date: Jun 2011
Posts: 2
Rep Power: 0
ritmat is on a distinguished road
hello all,
I want to determine my required opening size for natural ventilation in a closed building. Inside there is a source of heat that I modeled as a rectangle and heat flux BC. In reality that surface is isolated so the temperature should not be more than building temperature but I cant set heat flux and temp. at the same time.
My outside temperature is 25C, and I want to be able to keep 50C max in my building.
I have tried many things but I dont get any convergence or realistic results(boussinesq, transient...).
my inlet at the bottom is pressure inlet at 0barg and my outlet at the top is pressure outlet at also 0barg ( I am also a bit confused if I should put or not the hydrostatic pressure corresponding to rho*g*h at the outlet for taking account the 21m of my building or fluent take that into account....).
I tried to have as a start a rough structured mesh with edge size of 0.2 all over my geometry.
After calculatin of Ra, and boussinesq condition, i thought i could use laminar and boussinesq in steady to calculate, but since i dont get anything which looks right, I have a doubt on my way to determine those numbers.
I would be gratefull, if anyone with experience on this type of problem could help me.
ritmat is offline   Reply With Quote

Old   June 9, 2011, 04:22
New Member
Join Date: Jun 2011
Posts: 2
Rep Power: 0
ritmat is on a distinguished road
In fact my Ra is probably over 10^10, so I am running my model in transient with a k-epsilon model. But I would really like to have some advice about my BC and my previous questions.
thanks a lot
ritmat is offline   Reply With Quote


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
Fluent natural ventilation pressure boundary condition pierresandre FLUENT 24 November 8, 2011 15:32
Natural Ventilation Sean FLUENT 1 April 13, 2008 12:50
natural ventilation on buildings bill FLUENT 2 September 30, 2004 07:43
Natural ventilation estimation neihad Phoenics 3 April 1, 2002 02:36
Using Phoenics to simulate natural ventilation Amber Phoenics 2 December 31, 2000 02:38

All times are GMT -4. The time now is 22:27.