Impact of exponential outer velocity on Casson nanofluid flow past an exponentially stretching sheet in presence of multiple slips

Abstract

A theoretical study is presented to reveal the features of non-Newtonian “nanofluid” flow past an exponentially stretching permeable surface in presence of exponential outer velocity and multiple slips at the boundary. Casson fluid model that accounts for the yield stress and shear-thinning behavior of the fluid is taken here to represent the non-Newtonian flow behavior. Casson nanofluid flow past an exponentially stretching surface has important practical applications in cooling of the electronic and industrial equipment, coating of various industrial items, glass manufacturing, biomedical processes etc. With the help of “similarity transformations,” the related equations and the boundary conditions of the flow problem are converted to self-similar forms. Numerical solutions are obtained using “Runge–Kutta method” with “shooting technique” and the effects of various parameters are analyzed in detail. Compared to the results considering no-slip at the boundary, the flow velocity and thermal characteristics are significantly altered when partial slips are considered. Due to exponential outer velocity, enhancement in flow velocity is observed. Though the fluid velocity increases but the temperature diminishes with the rise in the values of velocity ratio parameter. The findings of this study make a significant contribution by presenting non-Newtonian nanofluid’s behavior due to an extended surface in a moving free stream leading to a better understanding of the features of flow, transmission of heat and mass and offering insights for enhancing relevant engineering applications.