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

2nd derivative on nonorthogonal FV-mesh

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 1, 1999, 11:11
Default 2nd derivative on nonorthogonal FV-mesh
  #1
Thomas Wolfanger
Guest
 
Posts: n/a
Hi, I'm trying to implement an nonlinear boussinesq model to a FV-code. The nonlinear model is from Speziale (see "On nonlinear models of turbulence", Journ. Fl. Mech, 1986 I think) and contains terms with second derivatives of the velocity. How is it possible to calculate the second derivative in 2D on a nonorthogonal FV-mesh, especially at the boundaries, and how to avoid oscillatory solutions ?
  Reply With Quote

Old   June 29, 1999, 12:00
Default Re: 2nd derivative on nonorthogonal FV-mesh
  #2
D.M. Lipinski
Guest
 
Posts: n/a
Sorry for the late reply. When you use the FV approach, you should integrate your equations in the first step. The integrals over volume should be converted to the integrals over surfaces which normally leads to decreasing the orded of the integrand by one. Then your problem will be only to supply the approximation for the first derivative, which should not be a problem. To calculate the derivative on the boundary, I would calculate it either from the appropriate boundary conditions. If you're talking about the surface of the inner element, then you can calculate the cell-centered derivative, and then move it to the cell face either by interpolation or by the expansion in Taylor series from the cell center.

regards DML
  Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[ICEM] Generating Mesh for STL Car in Windtunnel Simulation tommymoose ANSYS Meshing & Geometry 48 April 15, 2013 05:24
Converting Starccm+ mesh Ladnam OpenFOAM 0 September 14, 2011 07:30
2d irregular grid Remy Main CFD Forum 1 December 22, 2008 05:49
2nd order time discretization with dynamic mesh Jack FLUENT 1 October 28, 2008 09:07
basic of mesh refinement arya CFX 4 June 19, 2007 13:21


All times are GMT -4. The time now is 03:36.