Stationary material transport

Abstract

In this chapter we consider simple problems of stationary diffusive mass transport. In Sects. 15.1 and 15.2 we show that, since in general mass diffusion is non-linear, it is intrinsically more complicated than momentum diffusion (i.e., viscous flow) and heat diffusion (i.e., conduction). Then, in Sects. 15.3 and 15.4, we show that in the dilute case (e.g., a dilute contaminant in a water stream) mass transport problems are linear and hence they are identical to the respective heat transfer problems, as both diffusive and convective fluxes are linear functions of the concentration difference.