# porous resistance

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

 August 15, 2011, 13:50 porous resistance #1 Member   sajad Join Date: Nov 2010 Posts: 51 Rep Power: 8 Sponsored Links hi dear freinds. im modelling a porous region and in the inlet i set a constant pressure.suddenly in decreased.so the mass flow decreased.i decreased the resistance of porous region by "CEL" expression to obtain the first flow rate with this new pressure.the resistance decreased but massflow is constant. what is the problem in my modelling? can any body guide me? best regards/

 August 15, 2011, 18:51 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 13,737 Rep Power: 106 Can you describe what you are modelling, what the boundary conditions are and what you are trying to achieve?

 August 16, 2011, 05:35 #3 Member   sajad Join Date: Nov 2010 Posts: 51 Rep Power: 8 sure. i modelling a tube with constant diameter that have a porous domain at the end.inlet and outlet "BC" are constant pressure.at inlet when time is less than 0.2 "P=4000pa" is applied and after that inlet pressure suddenly decreased to 1000pa.at outlet "P=100pa" and is fixed during whole simulation.when inlet pressure is 4000pa the porous resistance is fixed to 10.but when it decreased to 1000 i decreased the resistance to gain the flowrate that was following in tube by pressure inlet 4000.i mean at first inlet pressure was 40000 and resistance was10 and flowrate was q1 now the inlet pressure is 1000 resistance decreased and i want again q1. in the run after pressure decreased resistance decreased but flowrate is fix relative to p=1000

 August 16, 2011, 06:45 #4 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 13,737 Rep Power: 106 Is it compressible or incompressible? If you want to control the flow rate then why don't you use a mass flow boundary condition?

 August 16, 2011, 07:48 #5 Member   sajad Join Date: Nov 2010 Posts: 51 Rep Power: 8 it is incompressible. my B.Cs are presure so i can not use massflow. i change the resistance of porous domain manualy 10,9,8,5,0.but massflow didnt change.so i think i define porous in wrong way. could you give me a refrence or an example of modelling porous in CFX.? thanks for your replying

 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 fpingqian FLUENT 42 March 8, 2017 01:27 Lukas STAR-CCM+ 21 March 7, 2012 03:05 VT_Bromley FLUENT 5 March 23, 2011 11:38 Wikie FLUENT 0 April 23, 2010 06:07 Desheng Kong Main CFD Forum 3 December 19, 2000 12:07