[bondscar]

#include "udf.h"
#include "mem.h"
#define MN(a, c) ((a) < (c) ? (a) : (c))
#define MX(a, c) ((a) > (c) ? (a) : (c))
#define MNMX(a, b, c) ((a) < (b) ? (b) : ((a) > (c) ? (c) : (a)))
int nCV2, nVAR, iCV2, iSCV2;
int iDENS, iVISC, iPRANDTL, iTEMP, iCOND, iH2, iH2O, iCO, iCO2, iPVMN_PVns, iPVMX_PVns;
int iOH, iCH4, iSCH4, iSH2, iSH2O, iSCO2, iSCO, iSOH;
float LowBoundPV, UpBoundPV;
float ChemDat[55000][150];
/************************************************** *****/


enum { CV1, CV2 };
/*#define nCV2 216*/
#define LowBoundPV 0.0
#define UpBoundPV 1.0


typedef struct { float cv2min; float cv2max; float variable; } struct_interpol;


struct_interpol Interpol_data(float cv2i, int index)
{
* * int j;
* * double cv2min, cv2max;
* * struct_interpol outputdata;


* * /********** MEAN REACTION PROGRESS VARIABLE **********/
* * j = MNMX((201 - 1) * (cv2i - LowBoundPV) / MX((UpBoundPV - LowBoundPV), 1.0e-6), 0, 201 - 2);


* * /********** INTERPOLATION VARIABLE FROM TABLE **********/
* * double f20 = (201 - 1) * (cv2i - LowBoundPV) / (UpBoundPV - LowBoundPV) - j;
* * double f21 = 1.0 - f20;


* * outputdata.cv2min = 10.0 * (j + 1); // Some sample data, replace with your actual data
* * outputdata.cv2max = 10.0 * (j + 2); // Some sample data, replace with your actual data


* * outputdata.variable = f20 * (10.0 * (j + 2)) + f21 * (10.0 * (j + 1)); // Linear interpolation, replace with your actual data


* * return outputdata;
}
/************************************************** **********/
DEFINE_ON_DEMAND(ReadData_FGM)
{
* * FILE *dat, *check;
* * char str[22];
* * struct_interpol input_data;


* * check = fopen("check.txt", "w");
* * /* READ CHEMICAL DATA FROM FGM.dat */
* * dat = fopen("FGM.dat", "r");
* * if (dat == 0) { fprintf(check, "Error: requested FGM datafile NOT found!\n"); }
* * else {
* * * * fscanf(dat, "%s\n", str);
* * * * while (strcmp(str, "[DATA]") != 0) {
* * * * * * if (strcmp(str, "[NUMBER_PV]") == 0) { fscanf(dat, "%i\n", &nCV2); }
* * * * * * else if (strcmp(str, "[NUMBER_VARIABLES]") == 0) { fscanf(dat, "%i\n", &nVAR); }
* * * * * * fscanf(dat, "%s\n", str);
* * * * }
* * * * fprintf(check, "GENERAL PARAMETERS FGM_PDF.dat:\n");
* * * * fprintf(check, "Number means CV2: %i\n", nCV2);
* * * * fprintf(check, "Number variables: %i\n\n", nVAR);
* * * * fprintf(check, "CHEMICAL DATABASE:\n");


* * * * for (i = 0; i < nVAR; i++) {
* * * * * * fscanf(dat, "%s", str);
* * * * * * fprintf(check, "%12s\t", str);
* * * * * * if (strncmp(str, "PV", 2) == 0) { iCV2 = i; }
* * * * * * else if (strncmp(str, "SourcePV", 8) == 0) { iSCV2 = i; }
* * * * * * else if (strncmp(str, "Density", 7) == 0) { iDENS = i; }
* * * * * * else if (strncmp(str, "Temperature", 11) == 0) { iTEMP = i; }
* * * * }
* * * * fprintf(check, "\n");


* * * * /* Scan chemical data from FGM.dat: */
* * * * for (i = 0; i < nCV2 * nVAR; i++) {
* * * * * * for (j = 0; j < nVAR; j++) {
* * * * * * * * fscanf(dat, "%e", &ChemDat[i][j]);
* * * * * * * * fprintf(check, "%e\t", ChemDat[i][j]);
* * * * * * }
* * * * * * fprintf(check, "\n");
* * * * }
* * * * fclose(dat); fprintf(check, "\n");
* * }
* * fprintf(check, "INDICES CHEMICAL DATABASE:\n");
* * fprintf(check, "Index CV2: %i\n", iCV2);
* * fprintf(check, "Index SCV2: %i\n", iSCV2);
* * fprintf(check, "Index Density: %i\n", iDENS);
* *
* * fclose(check);


}
/************************************************** ************************************/
DEFINE_PROPERTY(Density_FGM, c, t) {
* * double Rho;
* * struct_interpol input_data;


* * input_data = Interpol_data(C_UDSI(c, t, CV2), iDENS);
* * Rho = MNMX(input_data.variable, 1.0e-2, 1.0e1);


* * return Rho;
}



I am reading a data file which contains 201 rows and 116 columns of variables with headers as the names of those variables. Reading the file and storing is working also the interpolation function performs fine with a normal c compiler. I need to pass the interpolated values from the dat file to the fluent solver which is the function of this udf but it is getting the error mentioned below.



Node 0: Process 9812: Received signal SIGSEGV.




================================================== ============================




999999: mpt_accept: error: accept failed: No error




999999: mpt_accept: error: accept failed: No error


Also I liked to mention that chemdat array size is not required to be [550000][150] but some reason if the change the size it totally stoped working. In my file which is like 201*116 2D matrix.

[AlexanderZ]

what is this?

* * input_data = Interpol_data(C_UDSI(c, t, CV2), iDENS);

how and when are you going to obtain CV2? whats the range of possible values?

segmentation fault means you are trying to access value which doesn't exist

[bondscar]

From the dat file it should get the values. I have 201 CV2s which start from 0 and end at 1 with a 0.005 increment and for all those values I have corresponding density values in the data file, others can be calculated through the interpolation function. If those lines don't gonna work, can you suggest another line of code?

[AlexanderZ]

C_UDSI is a scalar macro at the specific finite volume (cell) , let's say velocity, pressure and so on

to be honest, your logic of reading from file is not clear for me
in general, I would read data from file to arrays
then I would somehow interpolate that data to my mesh (probably based on coordinates)

[bondscar]

input_data = Interpol_data(0.5, iDENS);
Rho = input_data.variable;

When I used the interpolation function like above it worked and no error occurred. But when I try to use C_UDSI(c,t,CV2) to get the return from the solver it brokes, and gives this:

Node 0: Process 13388: Received signal SIGSEGV.

================================================== ============================
The fl process could not be started.
Can anyone please help me to fix this line of code?

[AlexanderZ]

did you allocate memory for scalars in Fluent gui& you need to allocate 2 scalars

[bondscar]

I allocated one scalar and one memory from the GUI.

DEFINE_SOURCE(SourceCV2_FGM, c, t, dS, eqn) {
double scv2;
struct_interpol input_data;
input_data = Interpol_data(0.5, iSCV2);
scv2 = MNMX(input_data.variable, -1.0e6, 1.0e6);
C_UDMI(c, t, 7) = scv2;

dS[eqn] = 0.0e0;
return scv2;
}


I also have these lines of code, In this part, I can select from the fluid zone source term "User Scalar" where I have selected this particular source from the drop-down. But that also leads to the same error. Should I try with 2 scalars and then what number of User-defined Memory Locations is to be selected?

[AlexanderZ]

enum { CV1, CV2 };

means CV2 = 2, so you have to define 2 scalars, as you are using second one

C_UDMI(c, t, 7)

means you need at least 8 memory locations for udmi

[bondscar]

Still, I'm unable to set up the problem, I tried every viable process that I know to do it, but I am still getting the same error message
Node 1: Process 1580: Received signal SIGSEGV.
and in the end
The fl process could not be started.
please help me, set up the simulation in order because I think I am doing something wrong while setting up, the order in which the simulation must be set. In fluent I think that's a big concern.

[AlexanderZ]

show your code
describe in details how are you hooking functions in fluent gui

[bondscar]

thank you sir for your reply.
The problem I was facing was solved.

Regards
Ivan