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

When the velocity is small, the dynamic mesh doesn't move

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

Reply
 
LinkBack Thread Tools Display Modes
Old   January 3, 2011, 11:27
Default When the velocity is small, the dynamic mesh doesn't move
  #1
New Member
 
Join Date: Oct 2010
Posts: 4
Rep Power: 6
li2150 is on a distinguished road
My UDF is quite simple, but the velocity is very small:
DEFINE_CG_MOTION(plunge, dt, cg_vel, cg_omega, time, dtime)
{
cg_vel[0] = 1e-6;
}

When I set the time step size as 1s, the dynamic mesh moves correctly, but if I set the time step size as 0.1s, the dynamic mesh doesn't move. And with the time step size 0.1s but the velocity is 1e-5, the dynamic mesh can move again.

I guess that the product of velocity and time step size has to be larger than some particular value, but I don't know what this value is and how to change this value. I changed the mesh size and material, but the problem still exists.

Can someone help me? Thanks a lot.
li2150 is offline   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
3D Hybrid Mesh Errors DarrenC ANSYS Meshing & Geometry 11 August 5, 2013 06:42
Dynamic Mesh moving interface help akash.iitb FLUENT 0 August 23, 2010 23:53
dynamic mesh on a hexa grid Manoj Kumar FLUENT 0 August 21, 2007 07:41
Help: Is it possible to use dynamic mesh model and Valery Ponyavin FLUENT 1 September 20, 2003 14:18
Gambit problems Althea FLUENT 21 February 6, 2001 08:05


All times are GMT -4. The time now is 03:42.