  The main objective of this paper is to present a generic modelling framework,
for the diffusive mass transport through the turbulent, reactive boundary layer
of multi-component fluid mixtures that precipitate on the wall. The modelling
is based on Maxwell-Stefan diffusion in multi-component mixtures, the
relaxation to chemical equilibrium model, and the single-phase Navier-Stokes
equations. Final-ly, turbulence is introduced by Reynolds-averaging. The
governing equations are simplified in accordance with common assumptions of
computational fluid dynamics (CFD), and based on the assumption that the
over-all bulk flow is parallel to the wall, 1-dimensional equations for the
species and heat transport perpendicular to the wall have been formulated. The
equations are solved on a fine grid in order to fully resolve the boundary
layer, and the effect of allowing/disallowing deposition and chemical reactions
was investigated for a simplified test-case (4-component ideal mixture of
perfect gasses capable of chemical reaction and sublimation fouling).
  The developed framework can be employed as a sub-grid model for direct
precipitation/crystallization/solidifica-tion fouling in coarse grid CFD
models.
