December 28, 2020 at 7:52 pm

Konstantine Kourbatski

Ansys Employee

The answer is likely in the definition of molar and mass fractions. Mass fraction distribution along the surface looks to be constant (the artifact at the plate edge is probably due to the nodal interpolation due to post-processing). But why molar fractions should be constant? Find the relation between mass and molar fractions (an appropriate text book or web search should get you one), and you'll see that it's a function of molar weights. So if you have more than two species, and the other species vary along the surface, then the molar fraction will vary as well. n