Certain issues related to the equations of molecular transport by P. Kerkhof and M. Geboers

This paper discusses the equations for mass transport proposed by Kerkhof and Geboers. It is pointed out that these equations are essentially a special case of Müller׳s equations presented in 1968. It is shown that the concepts of individual species velocities and momentum balances, which play a central role in the theory, introduce certain conceptual and theoretical issues. Certain features, unique to the K-G equations, make them essentially different from the ordinary Navier-Stokes equations used in the classical diffusion theory. We suggest several improvements and indicate that they have to be supported by computational experimentation.