CFD Online Logo CFD Online URL
Home > Forums > OpenFOAM

Update internal mesh with a predicting equation instead of motion solver with diffus?

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

LinkBack Thread Tools Display Modes
Old   January 3, 2013, 09:03
Question Update internal mesh with a predicting equation instead of motion solver with diffus?
Join Date: Nov 2011
Location: Tongji University,Shanghai,China
Posts: 33
Blog Entries: 6
Rep Power: 7
sunliming is on a distinguished road
Update internal mesh with a predicting equation instead of motion solver with diffusivity?

Hi, everybody!

My channel has a wavy bottom wall, which can be described as y_wall(x,t)=a*sin(k*(x-c*t), i.e. a travelling sine wave. This could be achieved by adapting "waveDisplacement".

However, I have trouble with the diffusivity. None of the available diffusivity can satisfy my need. For it squeeze grids vertically above crests and stretch over troughs, squeeze makes the first grid spacing much too small, and stretch makes the first grid spacing even larger than the second. Any given point at the bottom wall can be crest at one time, but becomes trough the next time. So it's tricky to give a proper diffusivity. See attached pictures.

Yet, the grid points can be predicted only if the bottom wall position is known. The i_th point elevation y_i = y_0 * r^(i-1) + y_wall, where r is the expansion ratio, y_0 the first grid height.

Does anyone known how to update the internal points using a predicting equation rather the "diffusivity"? Where should I add it?

Best regards.
Attached Images
File Type: jpg overview.jpg (82.0 KB, 18 views)
File Type: jpg crest.jpg (68.7 KB, 17 views)
File Type: jpg trough.jpg (68.4 KB, 15 views)
sunliming is offline   Reply With Quote


diffusivity, dynamic mesh, fvmotionsolver, update mesh, wave propogation

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
SnappyHexMesh for internal Flow vishwa OpenFOAM Native Meshers: snappyHexMesh and Others 24 June 27, 2016 08:54
Dynamic mesh update problem. David FLUENT 3 March 15, 2012 06:02
TGridFluent mesh with internal by prism layer and internal face for diagnostic sponiar OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 2 March 30, 2009 15:02
How to control Minximum mesh space? hung FLUENT 7 April 18, 2005 09:38
Mesh generator and CFD solver Gennady Kireyko Main CFD Forum 0 May 6, 2001 11:13

All times are GMT -4. The time now is 17:27.