gradient of species mass fraction
I got a question. I am trying to calculate gradient of species mass fraction using macro "C_YI_G" in Fluent. However, the value of "C_YI_G" is either zero or not reaonable. I have checked the value of species mass fraction "C_YI" and it is reasonable. So i change to another way to calculate gradient of species mass fraction. First, i transfer value of species mass fraction to a User Defined Scalar (UDS) and then i calculate the gradient of this UDS by macro "C_UDSI_G". Then the gradient result is reasonable. Do you know what is the problem with gradient of species mass fracion "C_YI_G"? Thank you in advance.
