# Sunction Boundary Condition

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

 March 14, 2012, 12:37 Suction Boundary Condition #1 New Member   Akim Faisal Join Date: Jan 2012 Posts: 18 Rep Power: 7 Hi, I am trying to solve a problem in which the channel is rectangular and the bottom wall will have a suction, meaning the fluid near the bottom wall will go downward with a certain velocity. How would I specify such boundary condition in FLUENT? Thanks, Akim Last edited by Akim679; March 14, 2012 at 12:56. Reason: Typo

 March 15, 2012, 10:40 #2 Senior Member     Daniele Join Date: Oct 2010 Location: Italy Posts: 1,002 Rep Power: 19 Pressure outlet? I'm not sure if you can set a mass flow inlet or a velocity inlet and then if you can specify a negative value... I'm not sure I understand your proble..post a picture. Daniele

 March 15, 2012, 15:31 Porous wall #3 New Member   Akim Faisal Join Date: Jan 2012 Posts: 18 Rep Power: 7 Actually, My adviser told me to model a wall as a "porous wall" which will allow fluid to seep through. Is there a way to specify that in FLUENT? Thanks, Akim

 March 16, 2012, 01:04 #4 Member   Join Date: Mar 2011 Posts: 50 Rep Power: 8 put ur suction boundary as pressure outlet write a udf using DEFINE_PROFILE and place it on this boundary..should work I am doing the same thing except my boundary is oscillating suction and injection.

 March 16, 2012, 12:30 #5 New Member   Akim Faisal Join Date: Jan 2012 Posts: 18 Rep Power: 7 Would you kindly elaborate on writing the UDF on the "DEFINE_PROFILE". I'm not too sure on UDFs. Thanks, Akim

 March 16, 2012, 13:07 #6 Member   Join Date: Mar 2011 Posts: 50 Rep Power: 8 /************************************************** ********************/ /* unsteady.c */ /* UDF for specifying a transient velocity profile boundary condition */ /************************************************** ********************/ #include "udf.h" DEFINE_PROFILE(SJ_velocity, thread, position) { face_t f; begin_f_loop(f, thread) { real freq=25.; real vol=400.; real spd=vol/520.; real t = RP_Get_Real("flow-time"); F_PROFILE(f, thread, position) = spd*sin(freq*(t-0.075)*(2.*3.141592654)); } end_f_loop(f, thread) }

 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 HMR CFX 5 October 10, 2016 05:57 poplar OpenFOAM 3 January 14, 2015 03:37 Thomas P. Abraham Main CFD Forum 20 July 7, 2013 05:05 Mukund Pondkule Main CFD Forum 0 March 16, 2011 04:23 Peiyong FLUENT 1 November 10, 2006 12:44

All times are GMT -4. The time now is 02:00.