Entropy generation analysis of micropolar fluid flow through a vertical microchannel under the combined effect of Joule heating, viscous dissipation, and thermal radiation with convective boundary conditions

Abstract

ABSTRACT In this era of modern science, microfluidics has gained much importance in the field of research due to large-scale applications in science and engineering. Transfer of heat via nanofluids in microfluidics is the key concept of research. Therefore, here we have considered micropolar fluid for better heat transfer in vertical microchannel and discussed the influences of radiative heat flux, Joule heating, and uniform heat source/sink with viscous dissipation. The equations that govern the physical model are nondimensionalised by the application of suitable dimensionless parameters. Runge–Kutta–Fehlberg 4th−5th order method is applied for solving the non-dimensional governing ordinary differential equations, and precisely computed microrotation, velocity, and temperature profiles of micropolar fluid. The impacts of various factors on entropy generation and Bejan number are explored and analysed through graphs. It is investigated that a higher coupling number decelerates the fluid flow and reduces the temperature of the fluid. Further, minimum entropy generation can be attained by rising coupling number, Hartmann number, and radiation parameter.