[Musiek17]

Hello
I want to simulate a heat source (Goldak model) during TIG welding. Every time I add the UDF and I want to do the initialization, I get an error:
"the f1 process could not be started fluent"

#include"udf.h"
#define PI 3.14159
#define v 0.00833
#define Il 150
#define Ul 14.25
#define af 0.005
#define ar 0.01
#define b 0.005
#define c 0.006
#define r 0.005

DEFINE_SOURCE(heat_qian_source_moving,cell,thread, dS,eqn)
{
real xc[ND_ND],source;
real x,y,z,t;
C_CENTROID(xc,cell,thread);
x=xc[0];
y=xc[1];
z=xc[2];
t=RP_Get_Real("flow-time");

if(((x-r-v*t)*(x-r-v*t)/(af*af)+y*y/(b*b)+z*z/(c*c))<=1&&(x-r-v*t)>=0)

{
source=(2*af/(af+ar))*0.8*Ul*Il*6*sqrt(3)/(PI*sqrt(PI)*af*b*c)*exp(-3*(x-r-v*t)*(x-r-v*t)/(af*af)-3*y*y/(b*b)-3*z*z/(c*c));
dS[eqn]=0;
}

else if(((x-r-v*t)*(x-r-v*t)/(ar*ar)+y*y/(b*b)+z*z/(c*c))<=0);
{
source=(2*ar/(af+ar))*0.8*Ul*Il*6*sqrt(3)/(PI*sqrt(PI)*ar*b*c)*exp(-3*(x-r-v*t)*(x-r-v*t)/(ar*ar)-3*y*y/(b*b)-3*z*z/(c*c));
dS[eqn]=0;
}
{
source=0;
dS[eqn]=0;
}
return source;
}

[obscureed]

Hi Musiek17,

Your if...else structures are flawed. The first structure is this:

if(test1) {
  /* do stuff1 */
}else if (test2) {
  /* do stuff2 */
}

... and this does stuff1 or stuff2 or nothing.

Then your second structure is

{
   /* do stuff3 */
}

which always happens.

I think you probably intended this:

if(test1) {
  /* do stuff1 */
}else if (test2) {
  /* do stuff2 */
 }else{
  /* do stuff3 */
 }

But none of this explains why you would be getting such fatal errors. I think you need to make the test case even simpler to find the cause of these errors.
Good luck!
Ed