[flo90000]

Hello

I wrote a udf to move a reed valve in 6DOF and I want to calculate the moment in z to allow or not a rotation but when I compile my udf, it appears there are some mistakes. but I don't know how to resolve it. Someone can help me, pls?

thnak you for your help

#include "udf.h"
#include "math.h"

DEFINE_SDOF_PROPERTIES(Valve_6dof_ex, prop, dt, time, dtime)
{
  static real theta, cg_x, cg_y;
  static real NV_VEC(A);
  static real Mz, netmoment;
  Thread *t;
  Node *node;
  face_t *f;

  Mz = 0.0;
  t = DT_THREAD(dt);
  cg_x = 0.01625;
  cg_y = 0.0185;

  begin_f_loop(f,t)
    {
      F_AREA(A,f,t);
      Mz += F_P(f,t)*(A[0]*(NODE_Y(node)-cg_y)-A[1]*(NODE_X(node)-cg_x));
    }
  end_f_loop(f,t)

    prop[SDOF_MASS] = 0.00114;
  prop[SDOF_IZZ] = 0.000023;
  prop[SDOF_ZERO_TRANS_X] = TRUE;
  prop[SDOF_ZERO_TRANS_Y] = TRUE;
  prop[SDOF_ZERO_TRANS_Z] = TRUE;
  prop[SDOF_ZERO_ROT_X] = TRUE;
  prop[SDOF_ZERO_ROT_Y] = TRUE;
  prop[SDOF_ZERO_ROT_Z] = TRUE;
  prop[SDOF_LOAD_M_Z] = 9.81*0.0114*cos(DT_THETA (dt)[2])*0.0095;

  theta = DT_THETA(dt)[2];
  netmoment = Mz + prop[SDOF_LOAD_M_Z];

  Message("\n 2d_ex : theta_Z:%e,Mz:%e,Mass:%e,mom_tot:%e\n", DT_THETA(dt)[2],prop[SDOF_LOAD_M_Z],prop[SDOF_MASS],netmoment);

  if((theta<0)||(theta>0.087))
    {
      prop[SDOF_ZERO_ROT_Z]=TRUE;
      Message("Clapet_ex_bloqué");
    }
  else
    {
      prop[SDOF_ZERO_ROT_Z] = FALSE;
    }
}

errors:
valve__7.c: In function Valve_6dof_ex:
valve__7.c:19: warning: comparison between pointer and integer
valve__7.c:21: error: array subscript is not an integer
valve__7.c:21: error: array subscript is not an integer
valve__7.c:21: warning: left-hand operand of comma expression has no effect
valve__7.c:22: error: array subscript is not an integer

[pakk]

Let me show you the steps I took to debug your code.

I looked at the location of the first problem: line 19. (I compiled your code and it said line 18 to me, but that is not really important.)

I checked which line this was: it was the following:

 begin_f_loop(f,t)

This is such a common line in Fluent, so only three things could be wrong:
1. A typo in "begin_f_loop"
2. A problem with f
3. A problem with t
So I checked how you defined f and t, and looked at examples in the help where f and t were defined, and I saw that your f was wrong, it should be:

face_t f;

So without the star.

I changed this, and this time the compilation gave no errors. It did give a warning about "node" being uninitialized, you should look at that.

[flo90000]

Originally Posted by pakk

face_t f;

Thank you for your answer. I have another question. When I want to run it, fluent say me "receive a fatal signal(segmentation fault" in series and "Receive Signal SIGSEV" in parallel. It s due to an invalid memory reference. Will I add some parallel compiler? I try add some user defined memory.

[pakk]

Originally Posted by flo90000

Thank you for your answer. I have another question. When I want to run it, fluent say me "receive a fatal signal(segmentation fault" in series and "Receive Signal SIGSEV" in parallel. It s due to an invalid memory reference. Will I add some parallel compiler? I try add some user defined memory.

Don't bother with the compiler or the user defined memory.

Originally Posted by pakk

It did give a warning about "node" being uninitialized, you should look at that.

Do this instead. "node" is uninitialized, so it causes the invalid memory reference. Fix this. Why do you use "node"? What should it refer to?

[flo90000]

Originally Posted by pakk

Why do you use "node"? What should it refer to?

node refer me the postion of each node on the wall to get the distance between the node and the center of gravity to calculate the momentum in Z due to the pressure on it

[D.M]

Hello,
i don't know if this gonna help you with your problem or not cause i haven't checked all the lines of your code , but when you want to use node values in your udf you must loop over all the nodes on your face and access their global index , try to change your code like this:
#include "udf.h"
#include "math.h"

DEFINE_SDOF_PROPERTIES(Valve_6dof_ex, prop, dt, time, dtime)
{
static real theta, cg_x, cg_y;
static real NV_VEC(A);
static real Mz, netmoment;
int n;
Thread *t;
Node *node;
face_t *f;

Mz = 0.0;
t = DT_THREAD(dt);
cg_x = 0.01625;
cg_y = 0.0185;

begin_f_loop(f,t)
{
f_node_loop(f,t,n) /*n refers to the local index of nodes on a face*/
{
node = F_NODE(f,t,n); /*accesing global index of nodes*/
F_AREA(A,f,t);
Mz += F_P(f,t)*(A[0]*(NODE_Y(node)-cg_y)-A[1]*(NODE_X(node)-cg_x));
}
}
end_f_loop(f,t)


""" "node" is uninitialized""" this warning shows that you haven't defined "node" and it means that you should define nodes by their global index.
it is exactly like "Thread *t" , and few lines below that you have defined " t = DT_THREAD(dt) " , you should do the same for the nodes too!

sry i didn't check your code completely but i hope the udf above helps you a little bit.