CFD Online Discussion Forums - CX_Find_Cell_With

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Try and delete all the file writing stuff and just display it in the console using Message();

Also, CX_Find_Cell_With_Point might only work with 3d inputs, so try adding a third index to pt (pt[2]);. Also, I'm using "real" values instead of "static double", although "real" and "double" should be the same on 64-bit machines.
You should also have an if-condition, if the cell couldn't be found. Something like this: (I've not tested it).

Code:

#include "udf.h"

#include "cxndsearch.h"

static ND_Search *domain_table = NULL;



static float c_centroid[2];

static cell_t c;

static Thread *t;

static CX_Cell_Id *cx_cell;

real pt[3];

FILE *fp_p01;



DEFINE_EXECUTE_AT_END(execute)

{

#if !RP_HOST

        theta = theta + 0.001 * 10;

        xTheory = 0.17 + R * cos(theta);

        yTheory = 0.10 + R * sin(theta);

        

        pt[0] = xTheory;

        pt[1] = yTheory;

        pt[2] = 0.0;



        domain_table = CX_Start_ND_Point_Search(domain_table,TRUE,-1);

        cx_cell = CX_Find_Cell_With_Point(domain_table,pt,0.0);

        

        if (cx_cell) {

                c = RP_CELL(cx_cell);

                t = RP_THREAD(cx_cell);

                C_CENTROID(c_centroid,c,t);

                p01 = C_P(c,t);

        } else {

                Message("Could not find cell!\n"); 

        }

        domain_table = CX_End_ND_Point_Search(domain_table);

#endif

}

Quote:

Originally Posted by ASimonsen (Post 631287)

Code:

#include "udf.h"

#include "cxndsearch.h"

static ND_Search *domain_table = NULL;



static float c_centroid[2];

static cell_t c;

static Thread *t;

static CX_Cell_Id *cx_cell;

real pt[3];

FILE *fp_p01;



DEFINE_EXECUTE_AT_END(execute)

{

#if !RP_HOST

    theta = theta + 0.001 * 10;

    xTheory = 0.17 + R * cos(theta);

    yTheory = 0.10 + R * sin(theta);

    

    pt[0] = xTheory;

    pt[1] = yTheory;

    pt[2] = 0.0;



    domain_table = CX_Start_ND_Point_Search(domain_table,TRUE,-1);

    cx_cell = CX_Find_Cell_With_Point(domain_table,pt,0.0);

    

    if (cx_cell) {

        c = RP_CELL(cx_cell);

        t = RP_THREAD(cx_cell);

        C_CENTROID(c_centroid,c,t);

        p01 = C_P(c,t);

    } else {

        Message("Could not find cell!\n"); 

    }

    domain_table = CX_End_ND_Point_Search(domain_table);

#endif

}

Thank you so much. My problem has been solved with your help.

Trouble in running this code

Quote:

Originally Posted by ASimonsen (Post 610172)

Hi

I tool a look at it and figured out how to do it. Ansys has posted a note on their website (required user access):

Macro CX_Find_Cell_With_Point form has
changed from R11 to R14.5/R15.
Problem/Description:
Macro CX_Find_Cell_With_Point form has changed from R11 to R14.5/R15.
Solution:
Please use the following header files and format for new releases

Code:

#include <udf.h> #include "cxndsearch.h" static ND_Search *domain_table=NULL; DEFINE_ON_DEMAND(locate_cell) { CX_Cell_Id *cx_cell; real tmpp[ND_ND]; . . . domain_table = CX_Start_ND_Point_Search( domain_table,TRUE,-1); cx_cell = CX_Find_Cell_With_Point(domain_table,tmpp,0.0); domain_table=CX_End_ND_Point_Search(domain_table); . . /* Can save domain table as a static pointer so that you can check if it's been created yet and not recreate it every time. */ .}

After messing around with it I found a way to locate the cell:

Code:

#include <udf.h>

#include "cxndsearch.h"



static ND_Search *domain_table = NULL;



DEFINE_ON_DEMAND(locate_cell)

{

        cell_t c;

        Thread *t;

        CX_Cell_Id *cx_cell;

        

        real P[3];

        real P_Cell[3];

        

        domain_table = CX_Start_ND_Point_Search(domain_table,TRUE,-1);

        for (int i = 0; i < 100; i++) {

                P[0] = 0.0;

                P[1] = 0.0;

                P[2] = (real)i / 100.0 * 5.0;

                

                cx_cell = CX_Find_Cell_With_Point(domain_table,P,0.0);

                if (cx_cell) {

                        c = RP_CELL(cx_cell);

                        t = RP_THREAD(cx_cell);

                        C_CENTROID(P_Cell,c,t);

                        Message("Found cell at [%g,%g,%g] with centroid [%g,%g,%g].\n",P[0],P[1],P[2],P_Cell[0],P_Cell[1],P_Cell[2]);

                } else {

                        Message("Could not find cell at [%g,%g,%g]!\n",P[0],P[1],P[2]);

                }

        }

        domain_table = CX_End_ND_Point_Search(domain_table);

}

Hello,
I would be really glad if someone could help me with my issue. I have tried running this code on ANSYS R 19.0 Academic version and it gives me the following error.

error C2664: 'CX_Find_Cell_With_Point' : cannot convert parameter 2 from 'real [3]' to 'double []'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

Thanks
Bhargav Sriram Siddani

Hi, youjfwhu!

If running fluent with multiple nodes, your udf code might generate
access-violation because of lacking search error treatment.
You should consider the case cx_cell = NULL.

CX_Find_Cell_With_Point() is run on all nodes containing partial mesh,
and does not always return valid cell ID.

Quote:

Originally Posted by siddanibhargav (Post 698933)

i met similar problem and solve it by using "compile" instead of "interpret".