Eur. Phys. J. Spec. Top. (2021) 230: 1399-1414
https://doi.org/10.1140/epjs/s11734-021-00051-x

Regular Article

Dispersion with wall absorption in non-Newtonian fluid flow subjected to external body acceleration

¹ Department of Mathematics, The University of the West Indies, Mona Campus, Kingston, Jamaica
² Department of Mathematics and Statistics, University of Technology, Kingston, Jamaica

^b nagarani_ponakala@yahoo.co.in

Received: 6 September 2020
Accepted: 31 January 2021
Published online: 6 May 2021

Abstract

The basic motive of this model is to understand the dispersion process of a solute in non-Newtonian fluid flow subjected to external body acceleration when taking into account the solute absorption at the tube wall. Generalized dispersion method approach is used and hence the local concentration is assumed as a series in terms of the mean concentration and its derivatives, with coefficients being functions of time. With this approach, the mean concentration is expressed in terms of three transport coefficients, namely the absorption, convection, and dispersion coefficients for the case of solute transfer at the wall. A finite-difference scheme is used to solve the intermediate equations in order to evaluate these transport coefficients. The effects of non-Newtonian rheology, pulsatile pressure gradient, external body acceleration, and the wall absorption on the dispersion coefficient and mean concentration are analysed. It is seen that the dispersion coefficient is affected by the presence of body acceleration as is evidenced by dramatic fluctuations in its magnitude during the course of the flow. We confirm that the peak of the mean concentration is dramatically reduced as the wall absorption coefficient increases, even in the presence of body acceleration. Based on the values of different parameters considered in the problem, the study can be applied to understand the dispersion phenomenon in narrow arteries.