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

Inlet Boundary condition

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 21, 2009, 04:41
Default Inlet Boundary condition
  #1
New Member
 
Satish
Join Date: Sep 2009
Posts: 3
Rep Power: 9
satish is on a distinguished road
I have modelled a rectangular duct open to atmosphere.How to give the inlet boundary condition such that the flow enters into the duct from all directions?
satish is offline   Reply With Quote

Old   September 21, 2009, 04:43
Default
  #2
Senior Member
 
ztdep's Avatar
 
p ding
Join Date: Mar 2009
Posts: 312
Rep Power: 10
ztdep is on a distinguished road
Send a message via Yahoo to ztdep Send a message via Skype™ to ztdep
Dear friends:
what is the meaning of "flow enters into the duct from all directions".
for the duct flow, we have inlet bc
regards
ztdep is offline   Reply With Quote

Old   September 21, 2009, 05:02
Default
  #3
New Member
 
Satish
Join Date: Sep 2009
Posts: 3
Rep Power: 9
satish is on a distinguished road
for eg.the inlet to draft fans in power plant..It is open to atmosphere and the flow enters from all directions into the suction chamber..
satish is offline   Reply With Quote

Old   September 22, 2009, 01:58
Default
  #4
Senior Member
 
ztdep's Avatar
 
p ding
Join Date: Mar 2009
Posts: 312
Rep Power: 10
ztdep is on a distinguished road
Send a message via Yahoo to ztdep Send a message via Skype™ to ztdep
for the inlet boundary condition, we must specify the magnitude and the direction of the speed.
ztdep is offline   Reply With Quote

Old   September 22, 2009, 04:26
Default
  #5
New Member
 
Shyam
Join Date: Apr 2009
Posts: 29
Rep Power: 9
shyamdsundar is on a distinguished road
If I understand correctly, you want to represent the flow dynamics at the duct inlet accurately. In that case, why don't you extend the computational domain little bit upstream of the duct and use the actual atmospheric/free conditions for inlet? Trying to formulate an accurate inlet is quite troublesome. It is better to keep this menace away from the physical problem of interest.

The best practice would be to make the duct inlet submerged in the flow. Have considerable grid points upstream and also a few grid points downstream of inlet. A similar approach applies to outlet as well.

Hope it helps.
shyamdsundar 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
ATTENTION! Reliability problems in CFX 5.7 Joseph CFX 14 April 20, 2010 15:45
inlet and outlet boundary condition for turbomachinery solution siamak1424 OpenFOAM 2 August 15, 2009 11:14
Inlet boundary condition ahsan FLUENT 1 July 29, 2009 19:23
Natural convection - Inlet boundary condition max91 CFX 1 July 29, 2008 20:28
Inlet boundary condition Araz FLUENT 1 February 22, 2005 07:46


All times are GMT -4. The time now is 16:57.