[Ahmed Hassan]

Hello everyone,
I'm trying to write a UDF for a thermal comfort index called PMV (predicted mean vote) but i'm getting this error when compiling in fluent:
line 95.. error C2063: 'PMV' : not a function
what could be the problem here ?
Thank you in advance

this is my code:

#include "udf.h"
DEFINE_ADJUST(pd_myudf,d)
{
Thread *t;
cell_t c;
real t_myudf = C_T(c,t)-273.15;
real speed_u_myudf = C_U(c,t);
real speed_v_myudf = C_V(c,t);
real speed_w_myudf = C_W(c,t);
real turbu_k = C_K(c,t);
real mh2o_myudf = C_YI(c,t,1); /*mass friction of h2o 1????*/
real clo = 0.55;
real icl_myudf = 0.155*clo; /*clothing insulation*/
real tr_myudf = t_myudf;
real M_myudf = 58.0; /*metabolism, w/m2*/
real W_myudf = 0.0;
real p_myudf = 101325.0;
real turbu_tu;
real speed_myudf;
real pa_myudf;
real speedv;
real speedw;
real speedu;
real fcl_myudf;
real tcl1_myudf;
real tcl_myudf;
real tcl2_myudf;
real hc_myudf;
real temperary1_myudf;
real temperary2_myudf;
real a_myudf;
real b_myudf;
real c_myudf;
real d_myudf;
real e_myudf;
real f_myudf;
real L_myudf;
real ppd_myudf;
real pmv_myudf;
thread_loop_c(t,d)
{
begin_c_loop(c,t)
{

/*calculate pa_myudf*/
speedu = speed_u_myudf;
speedv = speed_v_myudf;
speedw = speed_w_myudf;
speed_myudf = sqrt(pow((speedu),2.0)+pow((speedv),2.0)+pow((spee dw),2.0)); /*magnitude of speed*/
if (speed_myudf<0.05) {speed_myudf=0.05;} /*for speed<0.05,use speed=0.05*/
turbu_tu = 100.0*(turbu_k)/(speed_myudf);
pa_myudf = (29.0*mh2o_myudf)/((18.0+(11.0*mh2o_myudf))*p_myudf);


/*Calculate fcl*/
{
if (icl_myudf<0.078)
{fcl_myudf = 1.0+(1.29*icl_myudf);}
else
{fcl_myudf = 1.05+0.645*icl_myudf;}
}

/*iterate to calculate tcl*/

tcl1_myudf = 40.0;
tcl2_myudf = 35.7-(0.028*(M_myudf-W_myudf))-(icl_myudf*(0.0000000396*fcl_myudf*(pow((tcl1_myud f+273.0),4.0)-pow((tr_myudf+273.0),4.0))))+(fcl_myudf*hc_myudf*( tcl1_myudf-t_myudf));
{
if (tcl1_myudf-tcl2_myudf>0.000001)
{tcl1_myudf=tcl2_myudf;}
}
tcl_myudf=tcl2_myudf;

/*Calculate hc*/
temperary1_myudf = 2.38*pow((tcl1_myudf-t_myudf),0.25);
temperary2_myudf = 12.1*pow((speed_myudf),0.5);
{
if (temperary1_myudf<temperary2_myudf)
{hc_myudf=temperary2_myudf;}
else
{hc_myudf=temperary1_myudf;}
}


/*for a shorter formula of L_myudf*/
a_myudf = 0.0000000396*fcl_myudf*(pow((tcl1_myudf+273.0),4.0 )-pow((tr_myudf+273.0),4.0));
b_myudf = fcl_myudf*hc_myudf*(tcl_myudf-t_myudf);
c_myudf = 0.00305*(5733.0-(6.99*(M_myudf-W_myudf))-pa_myudf);
d_myudf = 0.42*(M_myudf-W_myudf-58.15);
e_myudf = 0.000017*M_myudf*(5867.0-pa_myudf);
f_myudf = 0.0014*M_myudf*(34.0-t_myudf);
L_myudf = (M_myudf-W_myudf)-(a_myudf+b_myudf+c_myudf+d_myudf+e_myudf+f_myudf);


/*Calculate pmv_myudf*/
pmv_myudf(c,t)=((0.303*(exp(-0.036*M_myudf)))+0.028)*L_myudf;


/*Calculate ppd_myudf*/
ppd_myudf(c,t)=100.0-(95.0*exp(-0.03353*pow((pmv_myudf(c,t)),4.0)-0.2179*pow((pmv_myudf(c,t)),2.0)));
}
end_c_loop(c,t)
}
}

[pakk]

Line 95 is:

pmv_myudf(c,t)=((0.303*(exp(-0.036*M_myudf)))+0.028)*L_myudf;

Earlier, you defined pmv_myudf as

real pmv_myudf;

That means that pmv_myudf contains a single number.
But in line 95, you suddenly treat pmv_myudf as something that depends on c and t...


You can fix that by writing

pmv_myudf=((0.303*...

But you have another problem: your UDF does not do anything. It calculates a lot, but it does not do anything with the results of this calculation...
I can only guess what you need, but my guess would be that you want to store the PMV in something that you can access in Fluent. The correct location would be a User Defined Memory (UDM).


Make sure to add one UDM in Fluent, and then in your code make it

UDM(c,t,0)=((0.303*...

By the way: you have the same problem for PPD.
So, add another UDM, and in your code use

UDM(c,t,1)=100.0-(95*...

Then, after running this UDF, you can plot these variables in Fluent just as you would plot the temperature or velocity.

[Ahmed Hassan]

Thank you very much for your time and well explained answer ...
your guess about storing the PMV and accessing it in cfd post is right.
The first thing i did was to set the number of user defined memory locations to 2....

After following your advice the error was gone, but i got this warning:
(6) : warning C4700: uninitialized local variable 't' used
(6) : warning C4700: uninitialized local variable 'c' used

i moved all my defined variables inside the loop, and the file compiled successfully.....After that i opened the Function Hooks and added my UDF in the adjust panel...
Now the case is initialized successfully, but when i run it i get the following error:

Node 0: process 5628: Received signal SIGSEGV
======================================
Node 1: process 6940: Received signal SIGSEGV
======================================
Node 2: process 7560: Received signal SIGSEGV
======================================
Node 3: process 7836: Received signal SIGSEGV
======================================
MPI application rank 0 exited before MPI_finalize() with status 2

i searched the forum for any helpful answer but without success, your help will be much appreciated.... Thanks in advance

this is my final UDF:

#include "udf.h"
DEFINE_ADJUST(pd_myudf,d)
{
Thread *t;
cell_t c;
thread_loop_c(t,d)
{
begin_c_loop(c,t)
{

real t_myudf = C_T(c,t)-273.15;
real speed_u_myudf = C_U(c,t);
real speed_v_myudf = C_V(c,t);
real speed_w_myudf = C_W(c,t);
real turbu_k = C_K(c,t);
real mh2o_myudf = C_YI(c,t,1); /*mass friction of h2o 1????*/
real clo = 0.55;
real icl_myudf = 0.155*clo; /*clothing insulation*/
real tr_myudf = t_myudf;
real M_myudf = 58;
/*metabolism, w/m2*/
real W_myudf = 0;
real p_myudf = 101325;
real turbu_tu;
real speed_myudf;
real pa_myudf;
real speedv;
real speedw;
real speedu;
real fcl_myudf;
real tcl1_myudf;

real tcl_myudf;
real tcl2_myudf;
real hm_myudf;
real temperary1_myudf;
real temperary2_myudf;
real a_myudf;
real b_myudf;
real c_myudf;
real d_myudf;
real e_myudf;

real f_myudf;
real L_myudf;
real ppd_myudf;
real pmv_myudf;
/*calculate pa_myudf*/
speedu = speed_u_myudf;
speedv = speed_v_myudf;
speedw = speed_w_myudf;
speed_myudf = sqrt(pow((speedu),2)+pow((speedv),2)+pow((speedw), 2)); /*magnitude of speed*/

if (speed_myudf<0.05) {speed_myudf=0.05;} /*for speed<0.05,use speed=0.05*/
turbu_tu = 100*(turbu_k)/(speed_myudf);
pa_myudf = (29*mh2o_myudf)/((18+(11*mh2o_myudf))*p_myudf);
/*Calculate fcl*/
{
if (icl_myudf<0.078)
{fcl_myudf = 1+(1.29*icl_myudf);}
else
{fcl_myudf = 1.05+0.645*icl_myudf;}
}

/*iterate to calculate tcl*/
tcl1_myudf = 40;

/*Calculate hc*/
temperary1_myudf = 2.38*pow((tcl1_myudf-t_myudf),0.25);
temperary2_myudf = 12.1*pow((speed_myudf),0.5);
{
if (temperary1_myudf<temperary2_myudf)
{hm_myudf=temperary2_myudf;}
else
{hm_myudf=temperary1_myudf;}
}

tcl2_myudf = 35.7-(0.028*(M_myudf-W_myudf))-(icl_myudf*(0.0000000396*fcl_myudf*(pow((tcl1_myud f+273),4)-pow((tr_myudf+273),4))))+(fcl_myudf*hm_myudf*(tcl1 _myudf-t_myudf));
{
if (tcl1_myudf-tcl2_myudf>0.000001)
{tcl1_myudf=tcl2_myudf;}
}
tcl_myudf=tcl2_myudf;

/*for a shorter formula of L_myudf*/
a_myudf = 0.0000000396*fcl_myudf*(pow((tcl1_myudf+273),4)-pow((tr_myudf+273),4));

b_myudf = fcl_myudf*hm_myudf*(tcl_myudf-t_myudf);
c_myudf = 0.00305*(5733-(6.99*(M_myudf-W_myudf))-pa_myudf);
d_myudf = 0.42*(M_myudf-W_myudf-58.15);
e_myudf = 0.000017*M_myudf*(5867-pa_myudf);
f_myudf = 0.0014*M_myudf*(34-t_myudf);
L_myudf = (M_myudf-W_myudf)-(a_myudf+b_myudf+c_myudf+d_myudf+e_myudf+f_myudf);
{
/*Calculate pmv_myudf*/
pmv_myudf=((0.303*(exp(-0.036*M_myudf)))+0.028)*L_myudf;
C_UDMI(c,t,0) = pmv_myudf;

}
/*Calculate ppd_myudf*/
ppd_myudf=100-(95*exp(-0.03353*pow((C_UDMI(c,t,0)),4)-0.2179*pow((C_UDMI(c,t,0)),2)));
C_UDMI(c,t,1) = ppd_myudf;
}
end_c_loop(c,t)
}
}

[hasnaabid]

I want to thank you for sharing your thermal comfort program. In fact, trying to run this program I got an error message: 'line 78: tcl1-myud: undeclared variable'.
I would be grateful if you help me overcome this problem

[pakk]

Check what line 78 in your code is...

[hasnaabid]

tcl2_myudf = 35.7-(0.028*(M_myudf-W_myudf))-(icl_myudf*(0.0000000396*fcl_myudf*(pow((tcl1_myud f+273),4)-pow((tr_myudf+273),4))))+(fcl_myudf*hm_myudf*(tcl1 _myudf-t_myudf));

[pakk]

And do you somewhere see the word "tcl1-myud"?
Once you found that, can you spot something wrong with it?