Learning Forum

[isaps1860]

I have an UDF Code in which the the velocity and the mass fraction should be read in and give out a value of a table which is coded in. Example of the code for the velocity and mass frac:

real xinput = C_U(c,t);

real yinput =C_YI(c,t,i);

For the velocity the code works and the code works fine if I put a value for C_YI(c,t,i) --> real yinput=0,19.

But if I let C_YI(c,t.i) in the code, I get an error code 999999 and fluent crashes...

Is there an additionally thing for the C_YI(c,t,i) macro I have to pay attention or what can be the problem?

[aitor.amatriain]

Have you defined the value of the species index (i)?

[isaps1860]

No I didn┬┤t define the value of the species index (i). Is this necessary? In the examples I have read there were no closer executions about i except the int i; -line

[aitor.amatriain]

Yes, you need to specify the species index

[isaps1860]

Thank you very much, is there an example for the specifying of the species index?

[aitor.amatriain]

As far as I am concerned, starting from 0, the order is the same as the list appearing in the "Mixture" section in the "Materials" panel.

[isaps1860]

Thanks for the answer but the problem still exists...Fluent also crashes with C_YI(c,t,0), C_YI(c,t,1) or other number values
Cannot understand why with C_U(c,t) everything is fine and with C_YI(c,t,i) theres a problem. Scheme is the same (except the i factor)

[aitor.amatriain]

Try to use C_YI in a simpler UDF (for example, you could define it as a post-processing variable by means of DEFINE_ADJUST macro).

[Rob]

As says C_YI(c,t,0) ought to pick up the first species in the mixture list. Please can you post the exact error message in it's entirety?

[isaps1860]

The exact error message in the console window is:
"999999: mpt_accept: error: accept failed: No error"
and this message several times before Fluent crashes and closes

[Rob]

That's a parallel code warning. Is there anything just above that?

[isaps1860]

Yes there┬┤s another error message above but because Fluent closes automatically after initializing or running the code, I couldn┬┤t get it. I will try to screenshot it on console if I will be fast enough :D

[isaps1860]

Node 0: Process 19356: Received signal. SIGSEV.
Is the first output in console after initializing or running

[aitor.amatriain]

Could you please shows us the UDF (code)?

[Rob]

So the value doesn't exist and is then called. Can you initialise and then hook up the code? You're defining real yinput =C_YI(c,t,i); but depending on the order things are called C_YI(c,t,i) has no value until it's initialised.

[isaps1860]

#include "udf.h"
#include
#include
DEFINE_SOURCE(source, c, t, dS, eqn)
{
Thread *tm=THREAD_SUPER_THREAD(t);
Thread **pt = THREAD_SUB_THREADS(tm);
Thread *tp = pt[0];
Thread *ts = pt[1];
Thread *sec;

real source;
int i;

typedef struct
{
double xCoordinate;
double yCoordinate;
double zCoordinate;
} Point;

int data[100];
int number_of_points = 25;
Point points[25];
int main();
{

Point test;
Point test2 ={1, 2, 3};
test.xCoordinate = 1;
points[0].xCoordinate = 0; points[0].yCoordinate = 0; points[0].zCoordinate = 0.0978;
points[1].xCoordinate = 0; points[1].yCoordinate = 0.10; points[1].zCoordinate = 0.068;
points[2].xCoordinate = 0; points[2].yCoordinate = 0.20; points[2].zCoordinate = 0.0532;
points[3].xCoordinate = 0; points[3].yCoordinate = 0.30; points[3].zCoordinate = 0.0132;
points[4].xCoordinate = 0; points[4].yCoordinate = 0.40; points[4].zCoordinate = 0.0324;

points[5].xCoordinate = 0.5; points[5].yCoordinate = 0; points[5].zCoordinate = 0.0244;
points[6].xCoordinate = 0.5; points[6].yCoordinate = 0.10; points[6].zCoordinate = 0.0166;
points[7].xCoordinate = 0.5; points[7].yCoordinate = 0.20; points[7].zCoordinate = 0.011;
points[8].xCoordinate = 0.5; points[8].yCoordinate = 0.30; points[8].zCoordinate = 0.05;
points[9].xCoordinate = 0.5; points[9].yCoordinate = 0.40; points[9].zCoordinate = 0.0092;

points[10].xCoordinate = 1; points[10].yCoordinate = 0; points[10].zCoordinate = 0.0264;
points[11].xCoordinate = 1; points[11].yCoordinate = 0.10; points[11].zCoordinate = 0.0148;
points[12].xCoordinate = 1; points[12].yCoordinate = 0.20; points[12].zCoordinate = 0.011;
points[13].xCoordinate = 1; points[13].yCoordinate = 0.30; points[13].zCoordinate = 0.0116;
points[14].xCoordinate = 1; points[14].yCoordinate = 0.40; points[14].zCoordinate = 0.0444;

points[15].xCoordinate = 1.5; points[15].yCoordinate = 0; points[15].zCoordinate = 0.0256;
points[16].xCoordinate = 1.5; points[16].yCoordinate = 0.10; points[16].zCoordinate = 0.0132;
points[17].xCoordinate = 1.5; points[17].yCoordinate = 0.20; points[17].zCoordinate = 0.0094;
points[18].xCoordinate = 1.5; points[18].yCoordinate = 0.30; points[18].zCoordinate = 0.0092;
points[19].xCoordinate = 1.5; points[19].yCoordinate = 0.40; points[19].zCoordinate = 0.258;

points[20].xCoordinate = 2; points[20].yCoordinate = 0; points[20].zCoordinate = 0.027;
points[21].xCoordinate = 2; points[21].yCoordinate = 0.10; points[21].zCoordinate = 0.014;
points[22].xCoordinate = 2; points[22].yCoordinate = 0.20; points[22].zCoordinate = 0.0106;
points[23].xCoordinate = 2; points[23].yCoordinate = 0.30; points[23].zCoordinate = 0.0122;
points[24].xCoordinate = 2; points[24].yCoordinate = 0.40; points[24].zCoordinate = 0.5102;

real xInput = C_U(c,tp);
real yInput = C_YI(c,ts,i);

printf("x = %.3f, y = %.3f", xInput, yInput);

Point neighbors[4];
neighbors[0] = points[0];
neighbors[1] = points[0];
neighbors[2] = points[0];
neighbors[3] = points[0];

for (int g = 0; g < number_of_points; g++)
{
Point currentPoint = points[g];

if (currentPoint.xCoordinate == floor(xInput))
{
if (currentPoint.yCoordinate == floor(yInput))
{
neighbors[0] = currentPoint;

}
if (currentPoint.yCoordinate == ceil(yInput))
{
neighbors[1] = currentPoint;

}
}

if (currentPoint.xCoordinate == ceil(xInput))
{
if (currentPoint.yCoordinate == floor(yInput))
{
neighbors[2] = currentPoint;

}
if (currentPoint.yCoordinate == ceil(yInput))
{
neighbors[3] = currentPoint;

}
}

if (currentPoint.xCoordinate <= xInput)
{
if (currentPoint.yCoordinate <= yInput)
{
if (xInput - currentPoint.xCoordinate <= xInput - neighbors[0].xCoordinate)
{
if (yInput - currentPoint.yCoordinate <= yInput - neighbors[0].yCoordinate)
{
neighbors[0] = currentPoint;
}
}
}
}

if (currentPoint.xCoordinate >= xInput)
{
if (currentPoint.yCoordinate <= yInput)
{
if (neighbors[2].xCoordinate < xInput)
{
neighbors[2] = currentPoint;
}

if ((currentPoint.xCoordinate - xInput <= neighbors[2].xCoordinate - xInput))
{
if (yInput - currentPoint.yCoordinate <= yInput - neighbors[2].yCoordinate)
{
neighbors[2] = currentPoint;
}
}
}
}

if (currentPoint.xCoordinate <= xInput)
{

if (currentPoint.yCoordinate >= yInput)
{

if ((xInput - currentPoint.xCoordinate <= xInput - neighbors[1].xCoordinate))
{

if (neighbors[1].yCoordinate < yInput)
{
neighbors[1] = currentPoint;
}

if (currentPoint.yCoordinate - yInput <= neighbors[1].yCoordinate - yInput )
{

neighbors[1] = currentPoint;

}
}
}
}

if (currentPoint.xCoordinate >= xInput)
{
if (currentPoint.yCoordinate >= yInput)
{
if (neighbors[3].xCoordinate < xInput)
{
neighbors[3] = currentPoint;
}

if ((currentPoint.xCoordinate - xInput <= neighbors[3].xCoordinate - xInput))
{
if (neighbors[3].yCoordinate < yInput)
{
neighbors[3] = currentPoint;
}
if ( currentPoint.yCoordinate - yInput <= neighbors[3].yCoordinate - yInput)
{
neighbors[3] = currentPoint;
}
}
}
}
}


double leftVertex = neighbors[0].zCoordinate + (neighbors[1].zCoordinate - neighbors[0].zCoordinate) / (neighbors[1].yCoordinate - neighbors[0].yCoordinate) * (yInput - neighbors[0].yCoordinate);
double rightVertex = neighbors[2].zCoordinate + (neighbors[3].zCoordinate - neighbors[2].zCoordinate) / (neighbors[3].yCoordinate - neighbors[2].yCoordinate) * (yInput - neighbors[2].yCoordinate);
double result = leftVertex + (rightVertex - leftVertex) / (neighbors[2].xCoordinate - neighbors[0].xCoordinate) * (xInput - neighbors[0].xCoordinate);
printf("result : %f\n", result);

source = result;

dS[eqn] = 0;
return source;
}
}

[isaps1860]

Thank you for the note, that this error means a value is missing. But the result by starting it after the initialisation is the same

[aitor.amatriain]

It seems that the value of the integer "i" is undefined

[isaps1860]

Yes, in the sended code there is no definition of "i". But I┬┤ve also tried with the definition of 0 and 1 and the code crashes
--> int i = 0; or also
--> C_YI(c,ts,0)

[aitor.amatriain]

Both species are present in both phase, right? If yes, either the second argument is wrong, or the macroC_YI is not valid for multiphase flows. I am not an expert in advanced multiphase macros, so I cannot help you.