Significance of Micro-Rotation on Buoyancy Driven Oscillatory Flow of Micropolar-Casson Fluid Through Tapered Wavy Channels: A Numerical Approach

The present study introduces a novel investigation into the heat and mass transfer in oscillatory micropolar-Casson fluid flow through a tapered wavy channel, considering both small and large values of plastic dynamic viscosity. The micropolar-Casson fluid models offer a novel perspective for understanding the complex dynamics of blood flow in restricted blood vessels. Incorporating micro-rotational effects and yield stress characteristics into these models provides a more comprehensive understanding of hemodynamic patterns and the potential for thrombosis. The objective of the study is to explore the novelty in the analysis of plastic dynamic viscosity through an asymmetric tapered wavy channel by examining its effect on the time-dependent oscillatory flow of a micropolar-Casson fluid in the presence of buoyancy forces and chemical reaction. The Plank's approximation is adopted to model the radiation component of heat transfer. An implicit finite difference numerical scheme called the Crank-Nicolson method is applied to solve the governing equations. Graphical analysis is employed to explore the influence of different physical parameters, including micropolar parameter, Peclet number, Hartmann number and transient. The numerical results of couple stress coefficient, heat and mass transfer rate are tabulated to highlight the significant effects of various fluid flow parameters. Higher values of the micropolar parameter, Lorentz force and micropolar-Casson parameter result in decreased velocity fields. For high values of Peclet number, there is a significant change in the fluid temperature between the centre of the channel and the right wall. The micropolar parameter plays a critical role in shaping fluid behavior by affecting microstructural interactions and fluid rotation. By scrutinizing the data points using slope regression analysis, it is noted that for both buoyancy and Lorentz force, the rates of couple stress coefficient are higher for larger plastic dynamic viscosity (PDV) values than smaller PDV values.