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

Pressure far field vs Velocity inlet/Pressure Outlet

Register Blogs Community New Posts Updated Threads Search

Like Tree6Likes
  • 6 Post By Santos-Dumont

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 29, 2013, 03:50
Default Pressure far field vs Velocity inlet/Pressure Outlet
  #1
New Member
 
Derek Kim
Join Date: Jan 2013
Posts: 15
Rep Power: 13
cocobi is on a distinguished road
Hello,

I just wanna ask you what's the difference btw 'Pressure Far Field' and 'Velocity Inlet and Pressure Outlet' when setting up the model of 2D airfoil (here, tried NACA 0012).

I tried both of them and found the following trends.

For the Pressure Far Field set,
Cd and Cl have a periodic trend on their graph and it repeated.

For the other case,
Even though the result of the two dimensionless factors showed a good convergence, the converged values were too far from the experimental ones.

So, I am wondering what I should look at when setting up the model for the boundary conditions.
cocobi is offline   Reply With Quote

Old   January 29, 2013, 11:45
Default
  #2
Member
 
Charles
Join Date: May 2011
Location: France
Posts: 77
Rep Power: 15
Santos-Dumont is on a distinguished road
It is pretty straightforward, you can easily find some things about that on the Fluent Theory Guide. Anyway the thing is that VelocityInlet/PressureOutlet are only used for incompressible cases only (velocity under Mach 0.3)

If you are compressible (this is usually set up by setting your material density to Ideal Gas and Viscosity to Sutherland) you shall use Pressure Far Field. You can use your entire boundary (i.e inlet, outlet and sides) and set it up as one single boundary in your meshing software, that saves time while setting up in Fluent.

So velocity inlet for incompressible, and pressure FF for compressible.
Santos-Dumont is offline   Reply With Quote

Reply


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
simple model, difficult outlet Eric CFX 7 May 23, 2014 09:13
How to get the velocity field from the pressure field Hermano Main CFD Forum 2 November 29, 2011 09:32
Physical meaning of pressure in pressure eqn dontknow Main CFD Forum 2 August 30, 2010 11:12
Help ASAP! pressure inlet & outlet engahmed FLUENT 0 June 13, 2010 16:33
Terrible Mistake In Fluid Dynamics History Abhi Main CFD Forum 12 July 8, 2002 10:11


All times are GMT -4. The time now is 04:36.