Adding new mass transfer model based on:
Cao, L., Sun, F., Chen, T., Tang, Y., & Liao, D. (2018).
Quantitative prediction of oxide inclusion defects inside
the casting and on the walls during cast-filling processes.
International Journal of Heat and Mass Transfer, 119, 614-623.
DOI:10.1016/j.ijheatmasstransfer.2017.11.127
The model calculates the oxide produced at the air-liquid interface of a VOF system.
A new BC was created to quantify the amount of oxide mass absorbed by walls.