Transport of reactive species in oscillatory Couette-Poiseuille flows subject to homogeneous and heterogeneous reactions

• Published in: Applied mathematics and computation Vol. 385; p. 125387
• Main Authors: Debnath, Sudip, Ghoshal, Koeli
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.11.2020
• Subjects: Axial-dispersion coefficient; Bulk flow reaction; Cross-sectional concentration; Integral moments; Poiseuille and Couette flows; Reversible and irreversible reactions; Poiseuille and Couette flows; Cross-sectional concentration; Integral moments; Axial-dispersion coefficient; Reversible and irreversible reactions; Bulk flow reaction
• ISSN: 0096-3003
• DOI: 10.1016/j.amc.2020.125387

•The study investigates the transport process by means of dispersion coefficient and cross-sectional distribution of solute.•Heterogeneous (reversible and irreversible) and homogeneous (irreversible) reactions are considered.•Three different kinds of flow pulsation have been considered.•The source of flow pulsation can affect the dispersion process by violating the actual nature of chemical reactions.•The cross-sectional distribution of solute strongly relies on the flow profiles rather than the rate of the reactions. The longitudinal dispersion and cross-sectional concentration distribution of chemical species through an annular tube have been studied for oscillatory flows in the presence of heterogeneous reactions between the species and tube wall along with homogeneous reaction in the bulk flow. The species is supposed to undergo kinetic reversible phase exchange and irreversible absorptive reactions at the outer wall material whereas in the bulk of the flow, the species participates in a first-order reaction with the solvent. The velocity distribution has a complex interaction with the reaction parameters and in order to track that, three different kinds of oscillatory flows are considered. For the purpose of estimation of dispersion coefficient, the method of moments Aris (1956)[3] is employed. The unsteady convective-diffusion equation gives rise to integral moment equations and are solved numerically by FDM. The cross-sectional concentration distribution is determined from the relationship between central moments and Hermite polynomials for the unsteady components of the flows. The study reveals the coupled effects of reversible phase exchange, irreversible absorption and bulk flow reaction on the transport of species in a variety of flow situations.