# [GAMBIT] periodic boundary condition for a rectangular duct domain

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

 May 24, 2013, 06:29 #21 Super Moderator     Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,080 Rep Power: 31 you can provide your mesh file, I can check but only on Monday. Are you sure you don't have this problem with symetry instead of periodic? What about wall instead of periodic? Give all the setup, density, viscosity etc... You are handling a domain with huge dimensions (order of 100 km), is it right? Seems to be quite big for a impeller if I refered to your picture, isn't it? __________________ In memory of my friend Hervé: CFD engineer & freerider

May 24, 2013, 07:29
#22
Member

Join Date: Mar 2013
Posts: 48
Rep Power: 4
Quote:
 Originally Posted by -mAx- you can provide your mesh file, I can check but only on Monday. Are you sure you don't have this problem with symetry instead of periodic? What about wall instead of periodic? Give all the setup, density, viscosity etc... You are handling a domain with huge dimensions (order of 100 km), is it right? Seems to be quite big for a impeller if I refered to your picture, isn't it?
yes max
i,m sure that with symmetry and with wall in stead of periodic there is no problem.
i,m simulating a wind turbine which the radios of it,s rotor is 63 meters
the radius of outer volume is 180 meters and the height of that is about 900 meters.
the other bcs and situation are as:
velocity inlet 11 m/s
pressure outlet 0 gauge
tow faces as interior
wind turbine wall
i,m starting with simple situation so i set my turbine as stationary wall and laminar situation.

 May 24, 2013, 07:43 #23 Super Moderator     Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,080 Rep Power: 31 2 points: * Domain Extents: x-coordinate: min (m) = -1.194447e+005, max (m) = -1.000000e+002 --> DX=119347m = 119 km y-coordinate: min (m) = -1.680000e+005, max (m) = 6.120000e+005 --> DY=780000m=780 km z-coordinate: min (m) = -1.200000e+005, max (m) = 6.000000e+004 --> DZ=180000m=180 km In Gambit how big is your outer volume? (Gambit has no unit, if you only import the mesh, then it is automatically scaled in m) *Did you specify your 2 faces as interior? (In Gambit, interior faces are automatically fused in interior domain). Do they appear as interior or wall in fluent? __________________ In memory of my friend Hervé: CFD engineer & freerider

May 24, 2013, 07:55
#24
Member

Join Date: Mar 2013
Posts: 48
Rep Power: 4
Quote:
 Originally Posted by -mAx- 2 points: * Domain Extents: x-coordinate: min (m) = -1.194447e+005, max (m) = -1.000000e+002 --> DX=119347m = 119 km y-coordinate: min (m) = -1.680000e+005, max (m) = 6.120000e+005 --> DY=780000m=780 km z-coordinate: min (m) = -1.200000e+005, max (m) = 6.000000e+004 --> DZ=180000m=180 km In Gambit how big is your outer volume? (Gambit has no unit, if you only import the mesh, then it is automatically scaled in m) *Did you specify your 2 faces as interior? (In Gambit, interior faces are automatically fused in interior domain). Do they appear as interior or wall in fluent?
i bring my geometry from catia into gambit,in catia they were in mm
so i interred my amounts in gambit with mm

i set that tow faces as interior in fluent too.

 May 24, 2013, 08:05 #25 Super Moderator     Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,080 Rep Power: 31 *then you have to scale your model *you cannot set your faces as interior in fluent, since they are not supposed to exist, except if you set them in Gambit. Did you set them in Gambit as interior? If not, then fluent shouldn't create them, and then something went wrong. __________________ In memory of my friend Hervé: CFD engineer & freerider

May 24, 2013, 18:09
#26
Member

Join Date: Mar 2013
Posts: 48
Rep Power: 4
Quote:
 Originally Posted by -mAx- *then you have to scale your model *you cannot set your faces as interior in fluent, since they are not supposed to exist, except if you set them in Gambit. Did you set them in Gambit as interior? If not, then fluent shouldn't create them, and then something went wrong.
dear max tnx really for all of your helps
i set the correct amounts for one of my walls and now it is working

 June 5, 2013, 07:48 #27 New Member   Avinash Join Date: Jun 2013 Posts: 1 Rep Power: 0 Select boundaries as " wall "type only then give the names to the boundaries such that you can easily identify the which boundary is periodic and his shadow. then In Fluent use command meshmodify zonesmake periodic give number of periodic and shadow boundaries use yes for rotational no for translation

 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 sunilpatil CFX 8 April 26, 2013 07:00 happy CFX 14 September 6, 2012 01:54 HMR CFX 3 March 6, 2011 21:10 Tudor Miron CFX 15 April 2, 2004 06:18

All times are GMT -4. The time now is 15:31.