CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

CFX steady simulation

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 7, 2010, 09:24
Default CFX steady simulation
  #1
New Member
 
Gareth
Join Date: Apr 2010
Location: Sydney Aus
Posts: 14
Rep Power: 15
gharek is on a distinguished road
Hi CFD users,

I am rather confused by the steady simulation in CFX. I'm using CFX 12.1. As far as I know, when assuming steady conditions, all the D(phi)/Dt terms are set to be equal to zero. Why is there a time step in CFX steady simulation?

So, if I am solving an unsteady and/or turbulent flow by assuming steady, would I get my residuals as fluctuating or divergent?

As far as I know from Fluent, there is no such timestep used for steady calculations.

Thanks for any advice.
gharek is offline   Reply With Quote

Old   April 7, 2010, 19:41
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
This is all explained in the documentation. The solver takes a psuedo-time stepping approach to convergence. Many other solvers take a under-relaxation approach to convergence and hence no time step is required - but you need to set under relaxation factors instead.

In CFX it is psuedo-time stepping as not all the transient terms are included and different equations can be advanced at different rates.
ghorrocks is offline   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
Small cluster configuration for pump simulation at CFX Nevel Hardware 2 April 7, 2014 07:07
steady simulation Rogerio Fernandes Brito CFX 5 August 9, 2008 21:22
2D simulation - ICEM meshing for CFX question Ben Makhal CFX 5 April 11, 2007 09:44
Simulation of turbine cascade in CFX. Jonas Pedro Caumo CFX 0 December 9, 2006 14:54
mesh from Workbench Simulation to Cfx Pre? Dai CFX 6 November 11, 2006 13:19


All times are GMT -4. The time now is 11:59.