CFD Online Logo CFD Online URL
Home > Forums > FLUENT

udf error

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

LinkBack Thread Tools Display Modes
Old   June 6, 2011, 23:33
Default udf error
Senior Member
Join Date: Nov 2009
Posts: 149
Rep Power: 7
wlt_1985 is on a distinguished road
I am new in using udf in fluent. I wrote udf to define properties of individual materials and their mixture. Some examples are shown as below:

DEFINE_PROPERTY(nitrous_oxide_viscosity, c, t)
real E; /* self-defined variable for convenience */
real mu; /* calculated viscosity in unit kg/m.s */
real T = C_T(c,t); /* temperature in unit kelvin, K */
const real A = 0.4733; /* dimensionless regression coeficient */
const real B = 21.8; /* dimensionless regression coeficient */
const real C = -0.004923; /* dimensionless regression coeficient */
const real D = -0.000004274; /* dimensionless regression coeficient */
E = A + B/T + C*T + D*T*T; /* self-defined variable for convenience */
mu = 0.001*pow(10, E); /* calculated viscosity in unit kg/m.s */
return mu; /* calculated viscosity in unit kg/m.s */

DEFINE_PROPERTY(mixture_thermal_conductivity, c, t)
real sum = 0.0;
int i;
Material *sp;
real ktc;
Property *prop;
mixture_species_loop(THREAD_MATERIAL(t), sp, i)
ktc = generic_property(c, t, prop, PROP_ktc, C_T(c,t));
sum += C_YI(c,t,i)*ktc;
return sum;

Error appears for simulation. 1 1.#QNBe+00 is shown for all residuals.

I did a check and found that udf causing the error. Can pls help me to check is there any mistake to my udf? I totally do not know what wrong is going on. Pls help.

Thanks for help.
wlt_1985 is offline   Reply With Quote

Old   November 15, 2013, 09:51
Join Date: Jun 2013
Posts: 50
Rep Power: 4
mehdimoradi. is on a distinguished road
Hello raymond
Could you sloved the problem associated with UDF?
I encountered with the same problem in running of species transport UDF. all of iterations are converged but donot display the residuals. in addition to .QNBe+00 is appered in the iterations.
Can you help me?

Last edited by mehdimoradi.; November 16, 2013 at 12:20.
mehdimoradi. is offline   Reply With Quote


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
ParaView for OF-1.6-ext Chrisi1984 OpenFOAM Installation 0 December 31, 2010 07:42
Accessing phi from a fvPatchField at same patch johndeas OpenFOAM 1 September 13, 2010 20:23
Installation OF1.5-dev ttdtud OpenFOAM Installation 46 May 5, 2009 02:32
Problem with compile the setParabolicInlet ivanyao OpenFOAM Running, Solving & CFD 6 September 5, 2008 20:50
Errors running allwmake in OpenFOAM141dev with WM_COMPILE_OPTION%3ddebug unoder OpenFOAM Installation 11 January 30, 2008 21:30

All times are GMT -4. The time now is 13:20.