Pressure correction BC using SIMPLE

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

 July 11, 2007, 08:19 Pressure correction BC using SIMPLE #1 AndrĂ© Gaathaug Guest   Posts: n/a Hi I just started a course in CFD at my masters education. I am working on my own CFD solver, but I found a bit of a problem defining the BC of the pressure-correction when using the SIMPLE algorithm. It's especially wall-BC for the pressure-correction I find hard, but also outlet-BC for pressure-correction. I find pressure-correction BC hard to figure out since they give no physical meaning to me at all. Please reply if you have a hint to the BC or know where I can find a hint. For visualization of velocities I just wonder about wether to use mean values for the x- and y-velocity, since I am using the backwards staggered grid and then no velocity is stored on the same place. Do I mean the values and place them in the centers as all the scalars?

 July 11, 2007, 16:07 Re: Pressure correction BC using SIMPLE #2 dontknow Guest   Posts: n/a Hi! Incompressible SIMPLE: -Inlet, Wall: massflux through boundary is given: massflux correction is zero, so pressure correction gradient is zero there and you have a Neumann Boundary-Condition -Outlet: Usually velocity is extrapolated and will be corrected to satisfy continuity. These corrected velocities are then considered to be fixed for the current iteration and so the massflux there is considered to be given. So you have Neumann Boundary conditions on all boundaries, the pc becomes singular and you have to fixe the pressure at one point to get a solution. For the compressible extension of SIMPLE all becomes a bit more complicated, look in the book by Ferziger and Peric! Good Luck...

 August 3, 2007, 01:38 Re: Pressure correction BC using SIMPLE #3 sekarapandian Guest   Posts: n/a dear Andre, First make sure that u-velocity and v-velocity points coincide with physical vertical and horizontal boundaries respectively. Accordingly, other boundary nodes lie outside the physical boundaries. This is the place where beginners struggle. For excellent explanation of implementation of boundary conditions, i suggest you to refer CFD book by Malalasekara & Versteeg. hope it helps.. Sekar...

 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 Giuki FLUENT 1 July 19, 2011 11:35 emlejeen FLUENT 4 August 7, 2010 06:45 Rooz Main CFD Forum 3 February 6, 2004 17:24 justentered Main CFD Forum 0 December 30, 2003 00:52 Dan Moskal Main CFD Forum 0 October 24, 2002 22:02

All times are GMT -4. The time now is 12:14.