[durg]

Hello!

I am defining an udf for my problem with define macros. I am defining array with 30 elements and want to initialize at time t=0. As we know that adjust get called at the beginning of the loop at every iteration. So, it gets initialized every time and old values get erased. It should be initialized at t=0 and keep on going with time. So, how do I initialize so that at any time it retain the values for that time?

Thank you!

[AlexanderZ]

make your array global so you can use it everywhere, initialize it in DEFINE_INIT macro


best regards

[durg]

Thank you. I tried that. But when I am printing the initialized values in adjust macros it is giving me 0 value instead of the desired value. I am initializing it with 0.0075 to all elements but on printing, it is giving '0'.

Now I am trying with 30(no. of elements) user-defined macros, which will store values at current time and can be used for next time step for particular cell. Here it is:

//Initializing
for(int j=0;j<30;j++)
C_UDMI(c,t,j)=0.0075;

Thank you

[AlexanderZ]

DEFINE_INIT(init_vars, d)
{
  cell_t c;
  Thread *t;
int j;
  
  thread_loop_c (t,d)
  {
    begin_c_loop (c,t)
    {
for(int j=0;j<30;j++)
C_UDMI(c,t,j)=0.0075;
    }
    end_c_loop (c,t)
  }
  
}

C_UDMI is user defined value at specific finite volume of your model, so you should organize loop over all finite volumes (cells) of your model and define values there

best regards

[annan]

Dear Durg,

Why didn't you define a matrix where for each time step you store the new values in an array with 30 elements ?

If you use User Defined Memory, then you have to loop on all the cells of your domain and store the value in all of them. If you make the array global, you can initialize it as Array[29] = {0.0075};

Good luck
Best regards
Annan

[durg]

Originally Posted by annan

Dear Durg,

Why didn't you define a matrix where for each time step you store the new values in an array with 30 elements ?

If you use User Defined Memory, then you have to loop on all the cells of your domain and store the value in all of them. If you make the array global, you can initialize it as Array[29] = {0.0075};

Good luck
Best regards
Annan

I tried by defining global like below:

real arr[30]={0.0075};
DEFINE_ADJUST(myad, d)
{
cell_t c;
Thread *t;
printf("Value %f\n", arr[2]);
d=Get_Domain(1);
thread_loop_c (t,d)
{
begin_c_loop(c,t)
{

------
}
end_c_loop(c,t)
}
}

for checking, I am printing one of the values of the initialized array and it is showing me 0 but it should be 0.0075. Am I doing right?

Thank you

[durg]

Originally Posted by AlexanderZ

DEFINE_INIT(init_vars, d)
{
  cell_t c;
  Thread *t;
int j;
  
  thread_loop_c (t,d)
  {
    begin_c_loop (c,t)
    {
for(int j=0;j<30;j++)
C_UDMI(c,t,j)=0.0075;
    }
    end_c_loop (c,t)
  }
  
}

C_UDMI is user defined value at specific finite volume of your model, so you should organize loop over all finite volumes (cells) of your model and define values there

best regards

Thank you. Yeah, I wrote in the same way and using this. Also I understand that these 30 udm will store 30 values for every cell and can be used for next time for new calculation and new values can be stored in again these 30 udm. Old value can be saved in other variable.

Please clarify.

Thank you

[AlexanderZ]

UDM is a variable which is defined in all cells , it may have different value in different cell.
Same UDM (for instance C_UDMI(c,t,0)) may have value =1 in the first cell (finite volume element of mesh) and value = 11 in cell number 2 and so on.
You may do with these values everything you want.

about other your question

real arr[30]={0.0075};
DEFINE_ADJUST(myad, d)
{
cell_t c;
Thread *t;
printf("Value %f\n", arr[2]);
d=Get_Domain(1);
thread_loop_c (t,d)
{
begin_c_loop(c,t)
{

------
}
end_c_loop(c,t)
}
}

your array arr consist of only 1 element
so if you want to pick first elemt from arry you should type

Message("Value %f\n", arr[0]);

it is recommended to you Message macro instead of printf in fluent UDF

best regards

[annan]

Originally Posted by durg

I tried by defining global like below:

real arr[30]={0.0075};
DEFINE_ADJUST(myad, d)
{
cell_t c;
Thread *t;
printf("Value %f\n", arr[2]);
d=Get_Domain(1);
thread_loop_c (t,d)
{
begin_c_loop(c,t)
{

------
}
end_c_loop(c,t)
}
}

for checking, I am printing one of the values of the initialized array and it is showing me 0 but it should be 0.0075. Am I doing right?

Thank you

Dear Durg,

If your compiler is GCC, this will definitely work :

real arr[30]={[0 ... 29] = 0.0075};
DEFINE_ON_DEMAND(Array_printing)
{
printf("Value %f\n", arr[2]);
}

I tested it and it worked

Good luck
Regards,
Annan

[durg]

Thanks a lot!!