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

Boundary conditions

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 12, 2002, 11:02
Default Boundary conditions
  #1
Glenn
Guest
 
Posts: n/a
Hi I have a small(I think) problem.Im modeling oscillating flow over a 2D circular cylinder. I have tried 2 sets of boundary conditions. The domain is rectangular and Im am using a structured mesh.

Firstly I tried with a velocity inlet on the lhs and a pressure outlet (set to 0) on the rhs. The velocity is set as Umax*cos(omega*t) where Umax=1. Now when I look at the velocity against time, the lhs gives a max velocity of 0.98 and rhs velocity gives 1.

For the second case I tried a pressure inlet and pressure outlet. The pressure was set according to du/dt=(-1/rho)*dp/dx where u is as above. This gives max velocity of 0.98 for both lhs and rhs.

Im using implicit, Quick, Presto and Piso solvers Can anyone explain why Im getting this slightly lower max velocity?? Thanks (and thanks to anyone who has helped me so far)
  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
symmetry boundary conditions in cfx lost.identity CFX 41 May 22, 2013 07:21
Impinging Jet Boundary Conditions Anindya Main CFD Forum 24 January 11, 2012 14:40
OpenFOAM Variable Velocity Boundary Conditions NickolasPl OpenFOAM Programming & Development 2 May 19, 2011 05:37
boundary conditions and mesh exporting vaina74 Open Source Meshers: Gmsh, Netgen, CGNS, ... 2 May 27, 2010 09:38
Trimmed cell and embedded refinement mesh conversion issues michele OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 2 July 15, 2005 04:15


All times are GMT -4. The time now is 06:04.