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Old   November 21, 2021, 00:26
Default call temperature in Profile UDF
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sina
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Hello,

In DEFINE_PROFILE , I want to call temperature of cell but when i run the file error "Node 0: Process 1404 : Received signal SIGSEGV" comes up .I'm sure problem because of C_T(c,t) .How can i call temperature in DEFINE_PROFILE?

here's my udf:

DEFINE_PROFILE(temperature_profile,t,i)

{

cell_t c;

float temparc;

float timeflow = CURRENT_TIME;

begin_c_loop(c,t)

{

if (timeflow>=0.021 || timeflow<=0.0346){

temparc=C_T(c,t);

F_PROFILE(c,t,i) =temparc;

}

else

F_PROFILE(c,t,i) =600;

}

end_c_loop(c,t)

}



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Old   November 21, 2021, 22:47
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Alexander
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instead of float use real

this UDF could work only in zones (not boundaries) apply it correctly.

put #include "udf.h" in the very first line
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Old   November 22, 2021, 09:05
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sina
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Thank you for your response, I used #include "udf.h" but I didn't copy here I forgot.
I have another problem I want to write profile (udf) which for specific time use tabular data and out of these time use the temperature that FLUENT is computed. but when i want to use temperature that FLUENT is computed it gets me the last temperature in tabular data how can I define that don't use these tabular data after specific time here is my part of code
/* Interpolate temperature from look-up table and assign to cell value */
DEFINE_PROFILE(temperature_profile,t,i)
{
cell_t c;
float time_flow = CURRENT_TIME;
float temparc;
float tempp=C_T(c,t);
begin_c_loop(c,t)
{
if (time_flow>=0.021 && time_flow<=0.0346){
temparc=get_tem_from_time(time_flow);
F_PROFILE(c,t,i) =temparc;
}else
F_PROFILE(c,t,i) =tempp;
}
end_c_loop(c,t)
}
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Old   November 22, 2021, 09:07
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sina
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Quote:
Originally Posted by AlexanderZ View Post
instead of float use real

this UDF could work only in zones (not boundaries) apply it correctly.

put #include "udf.h" in the very first line
Thank you for your response, I used #include "udf.h" but I didn't copy here I forgot.
I have another problem I want to write profile (udf) which for specific time use tabular data and out of these time use the temperature that FLUENT is computed. but when i want to use temperature that FLUENT is computed it gets me the last temperature in tabular data how can I define that don't use these tabular data after specific time here is my part of code
/* Interpolate temperature from look-up table and assign to cell value */
DEFINE_PROFILE(temperature_profile,t,i)
{
cell_t c;
float time_flow = CURRENT_TIME;
float temparc;
float tempp=C_T(c,t);
begin_c_loop(c,t)
{
if (time_flow>=0.021 && time_flow<=0.0346){
temparc=get_tem_from_time(time_flow);
F_PROFILE(c,t,i) =temparc;
}else
F_PROFILE(c,t,i) =tempp;
}
end_c_loop(c,t)
}
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Old   November 22, 2021, 22:59
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show code for get_tem_from_time function
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Old   November 24, 2021, 13:53
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sina
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Quote:
Originally Posted by AlexanderZ View Post
show code for get_tem_from_time function
#include "udf.h"

int NPts_tem = 111; /* number of entries in temperature table */

/* Locate the place in the interpolation vector using bisection algorithm*/

int locate(float xx[], int n, float x)
{
int j = 0;
int jm = 0;
int jl = 0;
int ju = n+1;
int ascnd = 0;

ascnd = (xx[n] >= xx[1]);
while (ju-jl > 1)
{
jm = (ju+jl) >> 1;
if (x >= xx[jm] == ascnd)
jl = jm;
else
ju = jm;
}

if (x == xx[1])
j = 1;
else if (x == xx[n])
j = n-1;
else
j = jl;

return j;
}

/* -----Understood------ */


float *time_vec_tem,*tem_vec;
#define FAST_LOOKUP TRUE /* use bisection algorithm for interpolation */

#define TABLE_MESSAGES TRUE
#define DISPLAY_TABLES TRUE

/* Obtaine mu given temperature */

float get_tem_from_time(float xdata)
{
int i = 0;
int j = 0;
float xL,xU,ydata;

#if FAST_LOOKUP
j = locate(time_vec_tem,NPts_tem,xdata);
xL = time_vec_tem[j];
xU = time_vec_tem[j+1];
ydata = tem_vec[j] + (xdata-xL)/(xU-xL)*( tem_vec[j+1] - tem_vec[j] );
#else
for ( i=1; i<NPts_tem ;i++ )
{
xL = time_vec_tem[i];
xU = time_vec_tem[i+1];
if ( (xdata>=xL)&&(xdata<=xU) )
{
ydata = tem_vec[i] + (xdata-xL)/(xU-xL)*( tem_vec[i+1] - tem_vec[i] );
break;
}
}
#endif

if ( xdata>time_vec_tem[NPts_tem] )
{
#if TABLE_MESSAGES
Message("n temperature is above the bound of visc-array n");
#endif
ydata = tem_vec[NPts_tem];
}
if ( xdata<time_vec_tem[1] )
{
#if TABLE_MESSAGES
Message("n temperature is below the bound of visc-array n");
#endif
ydata = tem_vec[1];
}

return ydata;
}

/* -----Understood------*/

/* Read in the data file containing temperature as a function of time */

DEFINE_ON_DEMAND(read_arctemperature)
{
int i = 0;
float xdata,ydata;
FILE* fp;

fp = fopen("arctemperature.dat","r");
if ( fp!=NULL )
{
#if !RP_NODE
Message(" \n");
Message("Reading file arctemperature.dat \n");
Message(" \n");
#endif
}
else
{
#if !RP_NODE
Message(" \n");
Message("Error opening file \n");
Message(" \n");
#endif
}

time_vec_tem = (float *) malloc(NPts_tem*sizeof(float)); /*Dynamic Memory Allocation*/

tem_vec = (float *) malloc(NPts_tem*sizeof(float)); /*Dynamic Memory Allocation*/

if ( (time_vec_tem==NULL)||(tem_vec==NULL) )
{
#if !RP_NODE
Message("Memory allocation error \n");
#endif
}

for ( i=1;i<=NPts_tem;i++ )
{
fscanf(fp,"%e %e \n",&xdata,&ydata);
time_vec_tem[i] = xdata;
tem_vec[i] = ydata;
#if DISPLAY_TABLES
#if !RP_NODE
Message("%e %e \n",time_vec_tem[i],tem_vec[i]);
#endif
}
#else
}
#if !RP_NODE
Message(" \n");
#endif
#endif

fclose(fp);
}


/* Interpolate temperature from look-up table and assign to cell value */
DEFINE_PROFILE(temperature_profile,t,i)
{
cell_t c;
float time_flow = CURRENT_TIME;
float temparc;
float tempp=C_T(c,t);
begin_c_loop(c,t)
{
if (time_flow>=0.021 && time_flow<=0.0346){
temparc=get_tem_from_time(time_flow);
F_PROFILE(c,t,i) =temparc;
}else
F_PROFILE(c,t,i) =tempp;
}
end_c_loop(c,t)
}
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