[Dinghc]

Hello everyone, I have a question that I would like to seek your advice on!

In the Eulerian Two-Fluids Model (also known as the Eulerian Model) of ANSYS FLUENT, I'm interested in utilizing a User-Defined Function (UDF) to access the interfacial area Ai of grid cells. This interfacial area Ai refers to the interfacial area of the mixture per unit volume in a two-phase flow. While examining the header files provided by ANSYS, I have come across two macros that might be capable of accessing Ai. However, I'm uncertain about the meanings of their parameters and haven't been able to find information about them in the user manual. Hence, I'm reaching out to all of you for guidance.

These two macros are MP_IAD_INDEX(i, j) and C_MP_AREA_DENSITY(c, t, index). The first macro seems to potentially return a parameter 'index' required in the second macro, but I'm unsure about this and I also lack a clear understanding of how these macros are employed.
Right now, my goal is to understand the functions of these macros and whether they can truly be employed to access the interfacial area Ai. Additionally, I'm uncertain about the role of parameter 't' and which thread it pertains to (mixture thread, primary phase thread, or secondary phase thread).

I genuinely appreciate your assistance and response!

[Dinghc]

The problem has been solved，Thanks！