# Unsteady BC

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

 LinkBack Thread Tools Display Modes
 November 25, 1999, 09:38 Unsteady BC #1 Morvan Dominique Guest   Posts: n/a Sponsored Links I would wish to impose unsteady boundary conditions by using software FLUENT5 and them User Defined Function (UDF) in interpreted mode. I tested the example developed in documentation entitled: " Transient Velocity Inlet Profiles for Flow in A Tube " To impose a condition speed of the form: Vx=V0+Asin(wt) I used the following procedure: #include "udf.h" DEFINE_PROFILE(unsteady_velocity,thread,position) { face_t_f; begin_f_loop(f,thread) { real t=RP_Get_Real("flow_time"); F_PROFILE(f,thread,position)=20.+5.*sin(10.t); } end_f_loop(f,thread)} By looking at the time evolution of the speed at the exit of the tube, I do not find a sinusoidale curve ? Did somebody of other encounter the same problem? Thank you in advance
 Sponsored Links

 November 25, 1999, 12:04 Re: Unsteady BC #2 ali Oge Guest   Posts: n/a Hi Morvan, I have done a lot calculation on pulsating flow in a muffler by using FLUENT 5. I have not faced any problem. I suggest you to monitor velocity variation especialy at the INLET and outlet boundaries at the each time step during the solution and check if your inlet velocity function is correct. And also, your time step should be enough small in order to define sine wave form of the inlet velocity. Ali,

 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 Christoph_84 FLUENT 0 February 25, 2010 12:06 dvdromnu OpenFOAM Running, Solving & CFD 5 November 9, 2009 03:15 Peter Pan Zhang FLUENT 2 June 11, 2006 19:53 zonexo Main CFD Forum 0 September 26, 2005 21:15 winnie FLUENT 1 April 28, 2003 11:30

 Sponsored Links

All times are GMT -4. The time now is 02:01.

 Contact Us - CFD Online - Top