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

UDF compilation and SIGSEGV error

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 14, 2024, 06:49
Default UDF compilation and SIGSEGV error
  #1
New Member
 
Roshan Shanmughan
Join Date: Jun 2017
Posts: 3
Rep Power: 9
roshan6890 is on a distinguished road
Hello all, I've compiled a udf which reads velocity data with corresponding time stamp from a .csv file using DEFINE_ON_DEMAND macro. Then, I use DEFINE_PROFILE to define an inlet velocity profile at flow-times corresponding to the time stamp. The udf works well on local machine but when I try to run it on a cluster, it crashes giving me the error "Node XX: Process XXXXX: Received signal SIGSEGV." I've tried to modify the udf by inserting "host_to_node_float" once the data is read using the DEFINE_ON_DEMAND udf. But, still the problem exists. Can anyone give me suggestions or ideas ? I'm posting the sample udf here.

"
#include "udf.h"

#define NPts 28 /* Number of data points */


/* Arrays for data */
float tDat[NPts], Uvel[NPts];
static int index = 0;

DEFINE_ON_DEMAND(VelRead)
{
FILE* fp;
char name[500] = "WeatherData.csv";
int i;

fp = fopen(name, "r");

if (fp == NULL)
{
#if RP_HOST
Message("\nError opening file: %s\n\n", name); // Dynamic file name in error message
#endif
return; // Exit if file is not opened
}
else
{
#if RP_HOST
Message("\nSuccessfully opened file: %s\n", name); // Confirm file opened successfully
#endif
}

// Skip the header
if (fscanf(fp, "%*[^\n]\n") == EOF) {
fclose(fp);
#if RP_HOST
Message("\nFailed to skip header in file: %s\n", name);
#endif
return;
}

for (i = 0; i < NPts; i++)
{
if (fscanf(fp, "%f %f \n", &tDat[i], &Uvel[i]) != 2)
{
#if RP_HOST
Message("\nError reading data at line %d in file: %s\n", i + 2, name); // +2 considering the header and 0-index
#endif
break; // Exit if data reading fails
}
#if RP_HOST
// Print each set of values read from the file
Message("Read values at line %d: Time = %f, Uvel = %f\n",
i + 2, tDat[i], Uvel[i]);
#endif
}

fclose(fp); // Always close the file

host_to_node_float(tDat, NPts);
host_to_node_float(Uvel, NPts);
Message("\nFinished reading data from file: %s\n", name);
}

DEFINE_PROFILE(vel_inlet_x, t, var)
{
real x[ND_ND];
real y;
real usX;
real time = CURRENT_TIME;
int newindex = -1;
face_t f;

for (int i = 0; i < NPts; i++) {
if (tDat[i] == time) {
newindex = i;
Message("\n index is %d\n", index);
}
}

if (newindex != -1) {
index = newindex;
}

Message("Uvel is %f ", Uvel[index]);

begin_f_loop(f, t)
{
F_CENTROID(x, f, t);
y = x[1]; // Assuming the y-coordinate is the second component
usX = Uvel[index];
F_PROFILE(f, t, var) = usX;
}
end_f_loop(f, t)
}

"

Last edited by roshan6890; June 14, 2024 at 10:16.
roshan6890 is offline   Reply With Quote

Old   June 20, 2024, 18:24
Default
  #2
New Member
 
hasnaa hasnaa
Join Date: Jun 2024
Posts: 5
Rep Power: 2
hasnaaoub is on a distinguished road
I am doing a CFD study on an electric car.
Currently, I am in the setup phase. I tried to integrate solar radiation using a function in the "User Defined" interface with C code. I tried to use the "Interpreted" extension, but I still encounter an error. When I try to use the "Compiled" extension, another error occurs.

Can you send me an example of a udf function that you have already used in your studies and that can be used in ansys?

Thank you in advance for your help.
hasnaaoub is offline   Reply With Quote

Reply

Tags
define_on_demand, parallel udf, sigsegv fault


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
Node 0: Process xxxx: Received signal SIGSEGV jmjohansen FLUENT 42 March 18, 2024 02:23
Installation error with SU2 - Adjoint cfd-jg SU2 Installation 0 December 18, 2023 07:55


All times are GMT -4. The time now is 02:28.