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We here discuss a novel bioinspired pumping mechanism of non-Newtonian fluids in a microfluidic configuration, consistent with the propagative rhythmic contraction–expansion of a membrane attached to the wall of the fluidic channel. We consider the Rabinowitsch model to represent the rheology of non-Newtonian fluids. By employing lubrication theory and approximating the underlying flow to be in the creeping regime, the transport equations governing the pumping process are framed pertaining to the chosen setup. The transport equations are then evaluated by employing a well-established perturbation technique. By depicting the flow velocity components, streamline patterns, and velocity contours graphically, we aptly discuss the flow structure developed in the flow pathway and demonstrate the eventual consequence of these flow parameters to the net throughput during both compression and expansion phases of the pumping process. Finally, by demonstrating a phase-space diagram, we also discuss the impact of fluid rheology and membrane kinematics on the pumping capacity. The results obtained from the proposed model establish that the net flow owing to propagative rhythmic membrane contraction strongly relies on exponent parameter M and rheological parameter β. These consequences are expected to be of substantial practical relevance in designing micropumps intended to yield unidirectional flow of the complex fluids with improved efficiency, commonly used in biochemical/biomicrofluidic applications. [ABSTRACT FROM AUTHOR]

The proposed work numerically investigates the buoyancy-driven flow of Casson fluid from a vertical wavy surface under the influence of a magnetic field and evaluates the underlying transport of heat in the free convective regime both quantitatively and qualitatively. Pertaining to this analysis, the primitive forms of coupled non-linear partial differential equations are evaluated with the help of an efficient and straightforward Crank–Nicolson implicit finite difference technique. By representing the graphical plots of flow velocity, temperature, and friction-factor coefficients, obtained for different physical parametric values pertinent to this analysis, we discuss the influence of the Hartmann number, surface waviness parameter, and rheological parameter of the fluid on the underlying thermohydrodynamics. In addition to the isotherm and streamline plots, by demonstrating the functional form, we discuss an extensive flow visualization technique that provides unique heat flow visualization for the wavy surface based on Bejan's heat function concept. The results indicate that for increasing the magnitude of the magnetic parameter, the evolution of isotherms, streamlines, and heatlines deviates periodically with a higher amplitude, which signifies the transfer of high heat energy as well as the efficient transport of heat in the convective regime. [ABSTRACT FROM AUTHOR]