# inlet turbulent B.C.

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

 September 21, 2003, 04:05 inlet turbulent B.C. #1 ROOZBEH Guest   Posts: n/a Hi; In a water tunnel test section , for example, what turbulent intensity and turbulent viscosity should I set for inlet boundary condition.

 September 22, 2003, 03:52 Re: inlet turbulent B.C. #2 thomas Guest   Posts: n/a Hey, It depends on your system. For my part I usually use the Hydraulic diameter boundary condition associate with the turbulent intensity. The turbulent intensity represent the Fluctuation capacity of your system compared to the velocity value. You need to know that between 1% to 10% there are strictly no differences in results. Bigger values can modify your final results in some cases. Hope this can help, thomas

 September 25, 2003, 04:58 Re: inlet turbulent B.C. #3 Chetan Kadakia Guest   Posts: n/a Yes I agree. Use Dh and I. If you don't know the I value, 5% would not be a bad guess. Some low intensity tunnels can get as low as .05%. If you have a screen or obstruction, you may have 10% or greater. For Dh, you know the tunnel height you are modelling, so you have that answer. I: Turbulent Intensity Dh: Hydraulic Diameter

 September 25, 2003, 07:07 Re: inlet turbulent B.C. #4 thomas Guest   Posts: n/a Hey, Just another quick note about using an hydraulic diameter inlet BC. Using the k-eps turbulent model this method can give you very low k-eps intial condition ( in case you intitialize your domain using 'inlet condition' ). Therefore you should ajust both values more correctly. It is generally admitted k around 0.0001 and eps 0.001 ... but theer again it can depend on your case. bye, thomas

 Thread Tools 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 On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post cfdiscool FLUENT 10 June 10, 2015 06:15 SalvoCalvo Main CFD Forum 0 March 11, 2010 07:52 Sachin CD-adapco 1 March 26, 2008 11:22 raivish CD-adapco 2 January 11, 2006 04:00 Andrew FLUENT 4 May 25, 2004 04:24

All times are GMT -4. The time now is 18:25.