Transport of Reactive Species in Oscillatory Annular Flow

Abstract

The present article purposes to investigate the solute dispersion through an annular pipe in the presence of heterogeneous chemical reactions among the species and wall of the annulus. The solute is considered to experience a kinetic reversible phase exchange with the inner wall layer and irreversible absorption into the wall. Two kinds of oscillatory flow (Poiseuille and Couette flow) are considered in order to track the complex interactions between the velocity distributions and the reaction parameters. The method of moments as proposed by Aris-Barton is used to determine the apparent dispersion coefficient. The moment equations has been solved by using a standard finite difference implicit scheme, valid for small as well as large times. Dispersion coefficient due to the combined effect of reversible and irreversible reactions has been discussed in a variety of flow situations. Dispersion coefficient may be enhanced owing to the reversible and irreversible heterogeneous reactions in the boundary. On the basis of flow characteristics, radius ratio provides a mixed behaviour of the dispersion coefficient. Dimensionless mass proves to be an increasing function of reversible and irreversible boundary reaction parameters.

Moment analysis of unsteady bi-component species (drug) transport with coupled chemical reaction in non-Newtonian blood flow

“…Therefore, we restrict attention to consider one species i.e., A. In consistency with the available literature [54,58], the dispersion coefficient of species A exhibits a pulsatile nature (see Fig 4a, b). At small times, the amplitude of the dispersion curve is not uniform and it exhibits a growth; however, at large time (t>0.4), the amplitude of the dispersion curve becomes stable.…”

“…By using the first five concentration moments, we can estimate the mean concentration of the species  , using the fourth-order Hermite polynomialssee [54,55]…”

On Dispersion of a Reactive Solute in a Pulsatile Flow of a Two-Fluid Model

“…Using homogenization method, Ng (2006) studied the influence of reversible and irreversible reactions on the transport process when fluid flows through a pipe and the same has also been studied by Paul and Mazumder (2009) considering the annularity of the pipe. Further, an analysis of dispersion under Poiseuille and Couette flow has been done by Debnath, Paul, and Roy (2018) where both the reversible and irreversible reactions exist at the inner wall of the annulus. In view of literature, the studies on the combined effect of reversible and irreversible reactions on dispersion have been mostly assumed in Newtonian fluids, though there is hardly any work which has considered the same for singlefluid Casson model or two-fluid, three-layer models.…”