# MUSCL Differencing Scheme

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

 July 15, 2010, 00:54 MUSCL Differencing Scheme #1 New Member   Robert Seeley Join Date: Jun 2009 Posts: 3 Rep Power: 8 I'm writing code to do MUSCL differencing on a structured grid. I'm modeling supersonic flow through an irregularly shaped duct. I understand how to do the interpolation to get the state vectors at the cell faces for the internal points, but it isn't clear to me what the best approach is to calculate the value of the state vectors at the cell faces for the cells on the boundary of the computational domain since the interpolations extend outside of the defined grid. I have constant flow into and out of the computational domain, so I assume I can just use the inlet values for the cells at i=-1 and the outlet values for the cells at i=imax+1. Where I run into issues is for the cell faces on the nodes that border the walls. Do I assume values for j=-1 and j=jmax are equal to 0 since there is no flow outside of the computational domain, assume those locations have the same values as that seen at the wall, or make some other assumption? Any advice would be appreciated. Thanks, Robert

 July 15, 2010, 08:49 #2 Senior Member   Join Date: Jul 2009 Posts: 191 Rep Power: 8 Most people use ghost cells - the grid is extended and values are loaded into the cells outside the flow domain using extrapolation consistent with the boundary conditions. These values then allow a full width MUSCL extrapolation to be performed. The ghost cells are usually constructed based on some reflection of the geometry (i.e. grid points) across the boundary surface.

 July 18, 2010, 11:38 #3 New Member   Robert Seeley Join Date: Jun 2009 Posts: 3 Rep Power: 8 agd, thanks for the reply. I had to do a bit of reading on how to best set up the ghost cells, but I think I have it now.

 June 12, 2014, 02:10 MUSCL for irregular structured mesh #4 New Member   Join Date: Jun 2014 Posts: 2 Rep Power: 0 Hi RSeeley i simulated several test case such as double mach reflection, mach 3 forward facing step flow in pure rectangular grid with MUSCL scheme, but i am very confused about irregular structured mesh in FVM approach with MUSCL scheme. can u help me to calculate Flux in 4 interface of cell? Thanks with best regards

 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 ANPDEstudent Main CFD Forum 1 June 26, 2010 23:57 Chandra Main CFD Forum 6 February 14, 2007 12:21 Gonski Main CFD Forum 15 January 28, 2007 18:00 alice FLUENT 2 March 21, 2004 08:30 Julie Polyakh CD-adapco 2 July 30, 2003 11:12

All times are GMT -4. The time now is 06:21.