Deposition patterns and dispersion in reactive channel flows

Abstract:

Flow of natural fluids is often associated with dispersion of dissolved chemical species and their surface deposition either by precipitation kinetics or aggregation. For most industrial or practical flows, this wall deposition has a detrimental effect that hiders transport by clogging or alters the fluid container; therefore it is important to gain a better understanding of transport in reactive flows and the range of deposition patterns developed.

 This talk has two main aims. Firstly, it is to present a combined theoretical and numerical approach to explore the diverse yet generic wall morphologies that develop in channel flows either due to precipitation kinetics or aggregation of spherical particles. These deposition patterns range from dendrites to needles and fan-like structures growing against the mean flow direction, and depend strongly on flow perturbations and dispersion properties. The second goal is to revisit classical Taylor’s theory of dispersion in turbulent pipe flows and to show that, in fully developed turbulence, it predicts a nontrivial connection between longitudinal dispersion and the turbulent energy spectrum that we can also test and observe in numerical simulations.