[zitash]

Dear researchers,

Hi!

I am trying to calculate the interfacial area out of the CFD results. The interfacial can be flame surfaces (which can be defined by the gradient of temperature) or two-phase interfaces (which can be defined by the volume fraction \alpha).

After some googling, I find some discussions on similar topics relevant to two-phase flow, such as

How to compute surface area of rising bubble

How to get the surface area between two phases in VOF model

and they recommended to use the following equation
surface area = sum ( Magnitude of Gradient(Alpha) * Volume)

Can any one help me to understand this equation?

Besides, that equations seems to be only correct for two-phase surface estimation (as alpha lies between 0 and 1 and it is normalized for two-phase flow). So, how to apply it in flame surface estimation?

Regards,
Zitash