Surface Intergal in UDF

    • mohanpannirselvam08

      I would like to write the following Suface intergation formula in a UDF. But i am not sure am i writing it properly. The formula does the following:

      • Get the (v^2+w^2) velocty component value at each face value of the intersection surface within my flow domain (treftz-Plane).

      • Then multiplied it with density and 1/2

      • Then multiplied it with the respective surface area of the face

      • finaly sum all the product value for each face on the the intersection face.

      I have done this with a custom field function dialog box (Image). However as i try to run it in a UDF fromat, i get a totaly different values. Why is this? Am i doing something wrong in the UDF? What macros should i use?

      Surface integration formulaTrfetz Planetrefttz plane in the flow domain at back of the wing


      #include "udf.h"
      enum {     w4 };


      Thread *t;     cell_t c;     int n;     Node *node;     face_t f;     


          {     begin_f_loop(f,t)    {  

                 C_UDSI(f,t,w4) = 0.5*C_R(f,t)*((C_V(f,t)* C_V(f,t))+(C_W(f,t)*C_W(f,t)));  




    • Rob
      Ansys Employee

      You want to have a look at custom field functions: that may be a better solution. 

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