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

Pressure farfield vs Velocity Inlet BC

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

Like Tree1Likes
  • 1 Post By DarrenC

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 15, 2009, 10:54
Default Pressure farfield vs Velocity Inlet BC
  #1
Member
 
Join Date: Sep 2009
Posts: 69
Rep Power: 16
DarrenC is on a distinguished road
Hi everyone,

First Post!! Hope you guys can help me out with my query.

I have a problem understanding the difference btw a pressure farfield and Velocity-inlet boundary conditions, and how they can be applied. Firstly let me describe my work.

Im setting up a transient simulation of a 3d wing transitioning from 0 - 15 degrees angle of attack. If I simulate this wing on air, I use ideal gas law and i can define a pressure farfield boundary condition. My farfield geometry is a huge sphere by the way and my wing geometry is in the middle of this sphere.

Now lets say I were to simulate this in a water medium, my farfield velocities will be much smaller and thus I will use a incompressible flow solution. But once I set density to constant, I will need to define a new type of BC for my farfield as pressure farfield does not work with incompressible flow. Now what type of BC should I set my farfield to? Velocity-Inlet?

Now I do not really understand how the velocity inlet BC works compared to pressure farfield. Mainly, will it even work with a spherical farfield boundary geometry, or do I have to split my sphere into 2 and define one as my inlet, and the other my outlet?

Also to give some more information about my simulation, I am using a UDF to change the velocity components of the flow at each time step to simulate the wing pitching up. Do you forsee any problems with this if velocity inlet is used?

I hope some of you can shed some light into this for me. Thanks in advance for your help.
jecs likes this.
DarrenC is offline   Reply With Quote

Old   September 16, 2009, 03:23
Default hi
  #2
Member
 
ANIL
Join Date: Apr 2009
Posts: 35
Rep Power: 16
makaero is on a distinguished road
My work is similar to you, but the domain for 3d wing i used is a cubiod....trying to solve using Pre-farfield BC for subsonic flow.

May i knw the significance of using a sphere domain? how does it defer from cuboid domain (a wing face attached to a face of cuboid and the other end is free)
makaero is offline   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
Pressure Rise Error emueller CFX 0 May 5, 2009 12:08
boundary condition velocity inlet dont have gauge pressure setting value? coolyihao FLOW-3D 0 March 17, 2009 11:17
Setting static pressure as the inlet BC ruined FLUENT 1 March 21, 2008 15:57
Question about pressure inlet boundary condition. Alina FLUENT 1 November 30, 2007 08:39
Reversed flow in pressure inlet eric FLUENT 3 January 26, 2004 21:04


All times are GMT -4. The time now is 10:09.