[by1704116]

Hello, my dears.
Here is my problem in detail.I have a set of values,and each of it corresponds to its specific cell. I want to assign each of them to the corresponding cell center, and calculate the gradient of these value to form a mass source in the right hand side of the continuity equation.
In one paper,it says that one could save data in a txt file,and use DEFINE_ON_DEMOND to read it, assign values to the cell center ,store into an array,and use a second order reconstruction technique to calculate the gradient.
However, the Fluent udf manual just mentions the inherent variables,such as C_U(c,t),C_R(c,t), to use Gradient or Reconstruction Gradient macro.
I could store data into an array, but I don't know how to assign it to specific cell, and how could I use udf marco to calculate gradient?
Could someone give me some suggestions on my problem?
Thanks a lot for reading my post.