Bilan d'aire interfaciale dans un mélange diphasique : approche locale vs approche particulaire

The interfacial area balance equation in a two-phase mixture looks quite different depending whether the area per unit volume is defined as: i) the sum of all the areas contained in the unit volume or ii) the sum of the areas of all the particles with their centers in this unit volume. We prove here the complete compatibility between the two balance equations and show their respective merits.