Entropy generation analysis of Hall current effect on MHD micropolar fluid flow with rotation effect

Abstract

Entropy generation in form of heat dissipation destroys useful energy which accounts for the underperformance and decrease in the thermodynamic efficiency of a system. Since micropolar fluid is used as a working fluid in many technological and industrial processes, it is therefore necessary to examine the influence of all factors that can enhance entropy production so as to achieve the best energy systems design. In this paper, the influence of Hall current and ion-slip on the entropy generation rate of micropolar fluid is investigated. An applied uniform magnetic field acts in a perpendicular direction to the flow of fluid. The nonlinear coupled partial differential equations used to model the micropolar fluid flow are transformed to ordinary differential equations by using appropriate similarity variables. The differential equations obtained are solved by applying differential transform method. The results for velocity profiles, temperature profile and microrotation are used to determine fluid irreversibility and Bejan number. To get a clearer view of the study, the effects of various parameters such as Hall, ion-slip, magnetic field and coupling number on primary velocity, secondary velocity, temperature profile, microrotation, entropy generation and Bejan number are presented and explained via plots. The results show that entropy generation is reduced as coupling number and magnetic parameter increase, Bejan number receives a boost with increase in coupling number and magnetic parameter. Furthermore, heat irreversibility is more dominant than fluid friction irreversibility at the region close to the channel walls.