Peristaltic flow of a hyperbolic tangent fluid with variable parameters

Abstract

This article investigates the peristaltic flow of a hyperbolic tangent fluid with variable viscosity and thermal conductivity through a vertical asymmetric channel. Consideration is given to the effects of viscous dissipation, chemical reactions, and convection heat at the channel walls. The relevant mathematical modeling incorporates lubrication approximation. The resulting system of highly non-linear differential equations is converted non-dimensional via suitable quantities. The non-dimensional parameters formed in viscosity or thermal conductivity are treated as variables. This treatment is the fundamental recommendation of the current study to avoid obtaining unrealistic results. Using the built-in package (ParametricNDSolve) in the computing program Mathematica, the analysis is performed numerically, and the results for temperature and concentration profiles in addition to the trapping phenomenon are shown through graphs. The major findings show that an increase in temperature is associated with a decrease in viscosity, whereas the opposite (unrealistic) behavior is maintained when the variable parameters are treated as constants. Results also indicate that the thermal conductivity at relatively low temperatures is enhanced, whereas the opposite trend is noted at higher temperature values. Potential applications for the current work include cooling techniques used in medical and industrial applications, food processing, and blood flow in microvessels.