Three-dimensional rotating flow of couple stress fluid with slip constraints and activation energy: a response surface and sensitivity analysis

Purpose This paper aims to present an analysis of the flow characteristics of a couple stress fluid in a rotating rectangular geometry with slip conditions for velocity, temperature and concentration. The phenomena of viscous dissipation and activation energy have been considered for a more accurate modeling of such flows. Design/methodology/approach The partial differential equations are simplified to nonlinear ordinary differential equations through similarity transformation and then numerically solved by the MATLAB bvp4c method. The impacts of various parameters like slip coefficient, Reynolds number, Eckert number, Schmidt number, magnetic field, rotation, radiation and activation energy have been investigated. Moreover, sensitivity analysis and Response Surface Methodology (RSM) are also used for identifying the influential parameters on the transport process. Findings As can be seen from the analysis, an increase in the couple stress parameter reduces fluid velocity, whereas an increase in the parameter for viscous dissipation improves the temperature profile. An increase in the activation energy parameter increases the thickness of the concentration boundary layer. In addition, the parameters of Prandtl and Eckert have more impact on the heat transfer process, while Schmidt and activation energy have a greater impact on the mass transfer process. Originality/value This study provides a holistic approach to understanding the effects of slip, rotation, magnetic field, thermal radiation, viscous dissipation and activation energy on three-dimensional flow in a couple stress fluid. The numerical–statistical approach adopted in this research helps gain insights into the interplay between parameters and paves the way for designing non-Newtonian fluids in industry.