CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

receive fluent received a fatal signal (Segmentation fault).

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 6, 2015, 15:50
Default receive fluent received a fatal signal (Segmentation fault).
  #1
New Member
 
Michigan
Join Date: Mar 2015
Posts: 1
Rep Power: 0
chenkaiqe is on a distinguished road
hi,
I have a UDF as,
#include "udf.h"
#include "mem.h"
DEFINE_PROPERTY(viscosity3, c, t)
{

real tt,time;
real Z;
real strain_rate_nu;
real yield_stress;
real vis;

tt=C_T(c,t);
strain_rate_nu=C_STRAIN_RATE_MAG(c,t);

Z=strain_rate_nu*1.0e-15*exp(196835.0/8.314/tt);
yield_stress = 188.68*log(pow(Z/6.26,1.0/5.06)+pow(pow(Z/6.26,2.0/5.06)+1.0,0.5));
vis=yield_stress*1e6/3.0/strain_rate_nu;
return vis;
}


but every time when I try to use this, the fluent received a fatal signal (Segmentation fault). shows, even when I try to run it without UDF and then put it back, the errors shows up, someone can help me ~~~~~~
chenkaiqe is offline   Reply With Quote

Old   March 10, 2015, 06:48
Default
  #2
Senior Member
 
Paritosh Vasava
Join Date: Oct 2012
Location: Lappeenranta, Finland
Posts: 732
Rep Power: 18
vasava will become famous soon enough
The only reason I can think of is that you have not activated the energy equation. Because of that the simulation can not access the temperature data via C_T(c,t).
vasava is offline   Reply With Quote

Old   March 10, 2015, 09:21
Default
  #3
Senior Member
 
Join Date: Nov 2013
Posts: 1,446
Rep Power: 20
pakk will become famous soon enough
Quote:
Originally Posted by chenkaiqe View Post
Z=strain_rate_nu*1.0e-15*exp(196835.0/8.314/tt);
Are you sure this equation has no typo's?

If I try a temperature of 300 Kelvin, then exp(196835.0/8.314/tt) is equal to 1.8e34. This number may be too big to hold, if you are running single precision.

If this equation is really what you want, then you might use some numerical tricks to make it numerically better:

Code:
Z=exp(196835.0/8.314/tt+log(strain_rate_nu*1.0e-15);
pakk is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fluent15: received a fatal signal (Segmentation fault) lcg44 FLUENT 4 August 29, 2016 13:19
Error: received a fatal signal (Segmentation fault). Revist Fluent UDF and Scheme Programming 1 December 12, 2014 14:18
FLUENT received fatal signal (ACCESS_VIOLATION) LemonPeng FLUENT 5 September 3, 2013 07:42
FLUENT received fatal signal (ACCESS_VIOLATION) jwt FLUENT 2 July 1, 2010 09:35
error while compiling the USER Sub routine CFD user CFX 3 November 25, 2002 16:16


All times are GMT -4. The time now is 19:41.