CFD Online Logo CFD Online URL
Home > Forums > Fluent UDF and Scheme Programming

UDF steady state to transient

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

LinkBack Thread Tools Display Modes
Old   December 20, 2012, 12:55
Default UDF steady state to transient
New Member
Join Date: Nov 2012
Posts: 5
Rep Power: 5
Vcent is on a distinguished road

After successfully using a UDF for a nonlinear velocity profile at an inlet in a steady state mode, I would like to run it in a transient mode. I added the factor time. However the function only runs with constants for "q" (see red part). Otherwise I get a error "divergence detected in AMG solver x-momentum".

After testing several parts, I think it has probably something to do with y=x[1] (see blue part). Does anyone know a solution?

#include "udf.h"

DEFINE_PROFILE(inlet_x_velocity, thread, index)
real x [ND_ND];
real y;
face_t f;
real t = CURRENT_TIME;
real q;

if (CURRENT_TIME <= 100000.0)
q = 2.0*pow((y/3.0),0.4);
q = 1;
F_PROFILE(f, thread, index)=q;
end_f_loop(f, thread);


Vcent is offline   Reply With Quote


state, steady, transient, udf, velocity

Thread Tools
Display Modes

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Steady or Transient noobies FLUENT 1 February 17, 2012 14:38
Constant velocity of the material Sas CFX 15 July 13, 2010 08:56
Steady State Vs Transient answers Kushagra CFX 6 July 6, 2008 22:41
Transient vs Steady State Adam CFX 1 April 12, 2007 11:34
About the difference between steady and unsteady problems Lisa Main CFD Forum 11 July 5, 2000 14:37

All times are GMT -4. The time now is 12:54.