# Boundary Conditions

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

July 7, 2013, 05:05
#21
New Member

Join Date: Jul 2013
Posts: 4
Rep Power: 6
Quote:
 Originally Posted by Thomas P. Abraham ;1866 Hello Everyone: I am trying to get the flow field over a car. I am having some trouble in understanding certain boundary conditions. The problem is as follows: The flow is incompressible I have a computational mesh over the surface of the car. I could apply velocity boundary condition at the inlet and pressure boundary condition at the outlet (I will make sure the exit length is long enough to make this boundary condition valid). I will apply wall boundary condition at the bottom. I have problem in understanding the rest of the boundary conditions. I have been recommended to use symmetry boundary conditions on the sides and the top. I know that when symmetry boundary condition is applied, the gradient across that boundary is zero. It acts as a mirror. This does not answer my question completely. My question is: What it physically means? Does it help to reduce the near wall effects? All your insights and advise is appreciated, Thomas
Hi Everyone,

I am also performing the similar kind of simulation (I am simulating and underwater vehicle which is ejecting gases out form its nose/mouth). I am not able to recognize which boundary condition i should use at the nose/mouth of my vehicle so that it can eject gases out while it is moving forward in sea.

{From relative motion analysis, I am keeping my vehicle stationary but moving fluid (seawater) exactly opposite in the direction, my vehicle was supposed to move in}

@Yung-Ming Chen- Moving object volume should be less then 5% of the computation domain. (This assumption produces the almost similar to the reality)

 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 Anindya Main CFD Forum 25 February 27, 2016 13:58 lost.identity CFX 41 May 22, 2013 07:21 NickolasPl OpenFOAM Programming & Development 2 May 19, 2011 05:37 vaina74 Open Source Meshers: Gmsh, Netgen, CGNS, ... 2 May 27, 2010 09:38 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 06:33.