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

Grid

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 17, 2000, 21:55
Default Grid
  #1
Tony Tonton
Guest
 
Posts: n/a
Hi! Can any one can tell me what is the difference between structred grid and unstructured grid. That is,what is a structured grid. thanking you in advance

Tony
  Reply With Quote

Old   February 17, 2000, 23:43
Default Re: Grid
  #2
Burley Wang
Guest
 
Posts: n/a
I've asked the same question at sci.physics.computational.fluid-dynamics

here is the answer posted by Bob. Thanks Bob.

***************** Very briefly there are mainly two types of grids, structured and unstructured (defined below - and we needn't really discuss chimera grids or other such constructs). Although CFD largely uses the former and structural mechanics the latter, there are now many CFD applications which use unstructured grids. A major difference between unstructured grids for CFD and those for structural mechanics arises largely from the differences in the phenomena being modeled by the respective sets of equations. For many structures, a rather coarse grain structure is needed, whereas for CFD, fine structure is almost always needed somewhere.

structured grid - one where there is a regularized numbering pattern corresponding to cell position. Typically this means that a numbering scheme based on grid indices is sufficient to determining the neighbors of a given cell. For instance, the 2D cell whose indices are (i,j) always has four neighbors (i+1,j), (i-1,j), (i,j+1), and (I,J-1). The only exception being at boundaries.

unstructured grid - one where there is no generally definable pattern for determining the neighbors of a given cell. Thus lists of cell neighbors must be kept. This sounds like a big disadvantage, and it is, but one big advantage the unstructured grids have over structured is that they can be generated extremely quickly and can easily pack cells into high gradient regions whereas this takes some effort for the structured grids.
  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
MapFields to New Grid For Extreme Grid Deformations due to Body Motion albcem OpenFOAM 0 May 5, 2009 14:17
Grid Adaptation Suresh FLUENT 0 October 15, 2003 13:18
GRID TO GRID INTERPOLATION in FLUENT calogero FLUENT 3 June 4, 2003 08:32
Combustion Convergence problems Art Stretton Phoenics 5 April 2, 2002 05:59
Troubles modelling flow through a grid Hans Klaufus CFX 1 June 28, 2000 16:43


All times are GMT -4. The time now is 12:26.