[uconcorde]

Hello,

I am trying to use ADJUST macro to get second derivatives of my converged velocity field, but I got all zero values. Here is the code and procedure I am using. Can you please help me to find any mistake I have?

# include "udf.h"

DEFINE_ADJUST(adjust_gradient,domain)

{

Thread *t;

cell_t c;

face_t f;

domain = Get_Domain(1);

thread_loop_c(t,domain)

{

   begin_c_loop(c,t)

   {

      C_UDSI(c,t,0) = C_DUDX(c,t); // calculate d2u/dx2

   }

   end_c_loop(c,t)

}

}

Procedure:

1) Open my .cas file

2) Interpreted udf

3) Open my converged .dat file

4) User defined -> Scalars -> 1 -> Solution Zones: all fluid zones; Flux Function: none; Unsteady Function: none

5) Solving -> deselect User Scalar 0

6) Run calculation for 1 time steps

7) Check contour plot of User Defined Scalar: all zero values.



Best,

Dv

[AlexanderZ]

you dont need scalar, change to udmi
you should allocate memory for UDMI

C_UDMI(c,t,0) = C_DUDX(c,t); // calculate d2u/dx2

best regards