# Boundary condition set up

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

 January 20, 2012, 22:40 Boundary condition set up #1 New Member   Join Date: Jan 2012 Posts: 2 Rep Power: 0 Hi All, I am working on my research project " prediction of wind loads on house roof during hurricance" where I have designed a house structure with 8 feet y-direction, 30 feet x-direction, 20 feet z-direction with roof socket of 2 inch and upstream, downstream set as 10 times volume of the geometry of house. I am confuse about setting the boundary conditions. I have taken velocity inlet and pressure outlet with house as wall but am confuse about the region between velocity inlet and wall of the house and from wall of the house to the pressure outlet, Can I take as outflow boundary condition for rest of the part?

January 23, 2012, 14:06
#2
Member

Join Date: Jun 2011
Posts: 83
Rep Power: 8
Quote:
 Originally Posted by p3vd Hi All, I am working on my research project " prediction of wind loads on house roof during hurricance" where I have designed a house structure with 8 feet y-direction, 30 feet x-direction, 20 feet z-direction with roof socket of 2 inch and upstream, downstream set as 10 times volume of the geometry of house. I am confuse about setting the boundary conditions. I have taken velocity inlet and pressure outlet with house as wall but am confuse about the region between velocity inlet and wall of the house and from wall of the house to the pressure outlet, Can I take as outflow boundary condition for rest of the part?

Outflow boundary condition is only recommended when you flow is steady and stable at the outlet, even minor back flow in the outlet can cause convergence issues. It is better to use velocity inlet as the inlet boundary condition and pressure outlet as the outlet boundary condition.

Do you have another boundary between inlet and the wall of the house and from the house to the outlet?

 January 24, 2012, 14:29 #3 New Member   Join Date: Jan 2012 Posts: 2 Rep Power: 0 Yes, I have bondaries beteween inlet to wall of house and from house to the outlet. I have taken it as symmetry. I m confuse regarding that part can I take it as symmetry or not? Also when i am defining as a symmetry and when I am opening my meshing into fluent it gives me the error of "Warning: mesh is not detected correctly" Also when I am using k-epsilon model, when I am running the calculation it gives me divergent result. What to do with this problem?

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post CFD XUE FLUENT 0 July 9, 2010 02:53 CFD XUE FLUENT 0 July 8, 2010 06:49 gameoverli OpenFOAM Pre-Processing 1 May 21, 2009 08:28 Mark CFX 6 November 15, 2004 16:55

All times are GMT -4. The time now is 15:45.