CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Time step when scaling up.

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

LinkBack Thread Tools Display Modes
Old   October 19, 2010, 09:32
Default Time step when scaling up.
New Member
Join Date: Oct 2010
Posts: 2
Rep Power: 0
LeCatnip is on a distinguished road
Hi there.

Im new to the forum, I have been attempting to scale a simple flow from a small scale to scaling up using a scale factor of 20,000 to a larger scale. I have achieved good results from the small scale models but not for the large.

The large scale works ok when using the same inlet speed as the small scale, but then I am deviding the inlet speed by 20,000 in order to re-create the same reynolds number, and this gives pretty crazy results. My question is should I also multiply the time step by a factor of 20,000 if i reduce the inlet speed by a factor of 20,000? And do i need to change the K and epsilon values for the Reynolds Stress turbulence model which I am using?

Thanks for your help. I hope that was clear enough.

LeCatnip is offline   Reply With Quote


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
Superlinear speedup in OpenFOAM 13 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36
Hydrostatic Pressure and Gravity miliante OpenFOAM Running, Solving & CFD 132 October 7, 2012 22:50
HELP! time step too small? meangreen Main CFD Forum 5 August 27, 2009 12:32
Overflow problem in steady simulation ReeKo CFX 11 October 8, 2008 17:57
Physical Reason for stability of Implicit Schemes? radhakrishnan Main CFD Forum 25 December 7, 2000 16:25

All times are GMT -4. The time now is 12:15.