[ahmadimo]

I am a beginner in UDF programming and am simulating a 2D gas-solid fluidized bed and want to add an arbitrary user variable (just for test) which holds : rho_g*rho_s. I want to calculate this variable in every cell and show it in post-processing section to view contours. I also want to print it in console. In this way, I have used DEFINE_ON_DEMAND(on_demand_calc) function the following way:

/**********************************************************************
UDF to Print a new user variable Rho_g*Rho_s in a multiphase flow.
***********************************************************************/
#include "udf.h"

DEFINE_ON_DEMAND(on_demand_calc)
{
Thread *thread_g, *thread_s;
real rho_g, rho_s;
cell_t c;
Domain *g; 
Domain *mix_domain;
Domain *s;
g= Get_Domain(2);/* gas phase */
s= Get_Domain(3);/* solid phase*/
mix_domain = Get_Domain(1);

Thread *mix_thread = Lookup_Thread(mix_domain,1);

thread_g = THREAD_SUB_THREAD(mix_thread, 0);/* gas phase */
thread_s = THREAD_SUB_THREAD(mix_thread, 1);/* solid phase*/


/* Loop over all cells */
begin_c_loop(c,mix_thread)
{
rho_g = C_R(cell, thread_g);
rho_s = C_R(cell, thread_s);
printf("\n rho_g*rho_s= %g\n",rho_g*rho_s);
C_UDMI(c,mix_thread,0) = rho_g*rho_s;
}
end_c_loop(c,t)
}

I can not compile or interpret this UDF. Could anybody kindly check to see if I am going the right way and what is the problem with it?

errors when compiling:

..\..\src\rho_gs.c(18) : error C2275: 'Thread' : illegal use of this type as an expression
        c:\program files\ansys inc\v130\fluent\fluent13.0.0\src\mem.h(744) : see declaration of 'Thread'
..\..\src\rho_gs.c(18) : error C2065: 'mix_thread' : undeclared identifier
..\..\src\rho_gs.c(20) : error C2065: 'mix_thread' : undeclared identifier
..\..\src\rho_gs.c(20) : error C2223: left of '->sub_threads' must point to struct/union
..\..\src\rho_gs.c(21) : error C2065: 'mix_thread' : undeclared identifier
..\..\src\rho_gs.c(21) : error C2223: left of '->sub_threads' must point to struct/union
..\..\src\rho_gs.c(25) : error C2065: 'mix_thread' : undeclared identifier
..\..\src\rho_gs.c(25) : error C2223: left of '->nelements' must point to struct/union
..\..\src\rho_gs.c(27) : error C2065: 'cell' : undeclared identifier
..\..\src\rho_gs.c(28) : error C2065: 'cell' : undeclared identifier
..\..\src\rho_gs.c(30) : error C2065: 'mix_thread' : undeclared identifier
..\..\src\rho_gs.c(30) : error C2223: left of '->storage' must point to struct/union

errors when interpreting:

Error: C:\Users\ahmadimo\Desktop\FV\Ellis\rho_gs.c: line 18: parse error.
Error: C:\Users\ahmadimo\Desktop\FV\Ellis\rho_gs.c: line 20: mix_thread: undeclared variable

[Sixkillers]

You declared variable cell_t c, but in your code you are using variable called "cell" (in C_R method). So that is error reported by my compiler (GCC). In addition, variables s and g are not used (that is just two warnings).

[ahmadimo]

You declared variable cell_t c, but in your code you are using variable called "cell" (in C_R method). So that is error reported by my compiler (GCC). In addition, variables s and g are not used (that is just two warnings).

Thanks for the reply. I corrected that , but the errors still remain. I think there might be a problem with this one:

Thread *mix_thread = Lookup_Thread(mix_domain,1);

but I am not sure what the problem is. Is the overall code doing the right thing? I would appreciate if someone could help me if I am going the right way or is it a better way of adding a new user-defined variable like the one I need (rho_g*rho_s).

Thanks
Amir

[shashank312]

Amir, did you solve it eventually? If yes, then how? I would appreciate the help.