Base Fluids, Its Temperature and Heat Source on MHD Couette–Poiseuille Nanofluid Flow through Slippy Porous Microchannel with Convective-Radiative Condition: Entropy Analysis

Abstract

The intention behind this research work is to analyze the flow, heat transfer and entropy generation in a vertical channel filled with a nanofluid. The vertical microchannel is made of two parallel porous and slippy plates. The hot fluid is injected from the left side and succeeded from the right side. Fluid flow within the channel is induced due to an applied favorable/adverse pressure gradient (due to Couette–Poiseuille flow), right plate movement, buoyancy force due to the temperature difference of the channel plates in the presence of heat generation/absorption inside the channel and subjected to a constant applied transverse magnetic field. The resulting governing equations are solved numerically by the shooting method. The conventional fluids are chosen as water, and ethylene glycol-water mixture. The nanoparticles are selected as Al₂O₃ and CuO. Nanofluids modeling, which takes care of base fluid temperature, Brownian motion, diameter and concentration of nano particles, and base fluid physical properties are considered here. Roles of pressure gradient P (at the inlet), temperature of base fluids, heat generation/absorption, the density of the nanoparticle volume fraction on flow and heat transfer characteristics (velocity and temperature distribution, Nusselt number (Nu) distribution, entropy generation and Bejan Number) are investigated here. How the sequence of appearance of curves of flow and heat transfer characteristics (due to variation of aforesaid parameters) are disturbed by the presence of injection/suction, radiation and convective boundary condition is discussed here. A critical analysis is conducted on the individual contribution of irreversibilities due to heat flow, fluid friction and Joule heating to the total entropy generation. At last, we try to find an optimum condition at which local and global entropy generation are minimally generated in the channel.