# Transition point prediction in Star CCM

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 LinkBack Thread Tools Search this Thread Display Modes
 April 22, 2018, 10:34 Transition point prediction in Star CCM #1 New Member   Rishabh Kumar Join Date: Sep 2017 Posts: 8 Rep Power: 7 I'm using Star CCM+ 12.02 for stimulating incompressible flow over an axisymmetric body. i need help regarding the following: how to know the transition point over the body and How can I see which part of the body is experiencing a laminar flow please LMK if any additional information is needed. thank you so much for your time!

 April 23, 2018, 09:52 #2 Senior Member   Matt Join Date: Aug 2014 Posts: 943 Rep Power: 16 Technically speaking, a transition point is a numerical construct that you impose on an analysis. Natural transition is not an instantaneous phenomenon but rather a process that happens over a region. You can determine the approximate location by looking at shear stress along the surface and when it jumps from low-to-high you can assume that the flow has transitioned. However; the when, where and how of this transition is greatly influenced by your model and physics setup. You should try to work some validation cases first so you understand how to get acceptable results that can be verified before trying to model something more complex.

 April 30, 2018, 22:59 #3 Senior Member   Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,240 Rep Power: 63 The wall shear stress check is a good one I think. Try plotting the ratio of the eddy viscosity to the effective viscosity (laminar + turbulent viscosity). When the ratio is very low then you're laminar, when it's positive then you're more turbulent. If you're using a transitional model, there is an intermittency variable which tells you how much time the flow spends in laminar vs turbulent state. 0 for always laminar, 1 for always turbulent and between 0 and 1 is transitional.

 Tags star ccm

 Thread Tools Search this Thread Search this Thread: Advanced Search Display Modes Linear Mode

 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 OffTrackbacks are Off Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post mariochelito FLUENT 0 March 25, 2017 14:36 firda Main CFD Forum 3 February 26, 2011 02:51 Rif Main CFD Forum 2 February 24, 2008 08:40 Chie Min CFX 5 July 12, 2001 23:19 Tim Franke Main CFD Forum 4 January 28, 2000 11:14

All times are GMT -4. The time now is 08:09.

 Contact Us - CFD Online - Privacy Statement - Top