Entropy generation minimization and nonlinear heat transport in MHD flow of a couple stress nanofluid through an inclined permeable channel with a porous medium, thermal radiation and slip

Abstract

Irreversible losses and heat transport in a magnetohydrodynamic flow of a viscous, steady, incompressible, and fully developed couple stress Al 2 O 3-water nanofluid through a sloping permeable wall channel with porous medium and under the effect of radiation heat flux and slip were analyzed. The fundamental equations were solved numerically by using Runge-Kutta together with the shooting technique and the results were in qualitative agreement with an exact solution obtained for a limit case. The impacts of couple stress, Darcy number, solid nanoparticle concentrations, conduction-radiation parameter, Hartmann number and hydrodynamic slip on flow, temperature, heat transport, and entropy production were examined. It was possible to achieve values of minimum entropy production not yet reported in previous studies. In this way, optimal values of couple stress and slip were obtained. The heat transport was also explored and optimal values of slip flow and conduction-radiation parameter with maximum heat transfer were found. Finally, in addition to the alumina, the distributions of velocity, temperature, and entropy generation in TiO 2-water and Cu-water were presented for different solid nanoparticle concentrations. It was obtained that the local entropy of TiO 2-water was lower than Cu-water and Al 2 O 3-water in the channel bottom region while it was greater in the upper region.

Effects of nonlinear thermal radiation on magnetized Al2O3${\rm Al}_2 {\rm O}_3$‐Blood${\rm Blood}$ nanofluid flow through an inclined microporous channel: An investigation of second law analysis

“…The irreversibility analysis of magnetohydrodynamic Casson nanofluid flow through an inclined microporous channel with the influence of nonlinear thermal radiation is discussed. Following the work presented by Rosales et al [32] and López et al [35], the following selection of parameters is held constant throughout the examination unless otherwise expressed. (𝐸𝑐 = 𝑅𝑒 = 𝑃 = 𝐵𝑟 = 𝐷𝑎 = 𝑃𝑟 = 1, 𝛽 = 𝑀 = 𝐵𝑖 = 𝐺𝑟 = 0.5, 𝑅𝑑 = 𝜃 ℎ = 1.5, 𝛾 = 𝜋∕3, 𝑄 = 0.2, 𝑆 = 0.1, 𝜙 = 0.1).…”

“…[1] and Rosales et al. [32]): $$$$\begin{align} C_f &= {\left(1 + \frac{1}{\beta} \right)} {\left(\frac{d u^{\prime}}{dy^{\prime}} \right)},\nonumber\\ Nu &= - \frac{a {\left(k_{nf} + \frac{16 \sigma T^{3}}{3k^{*}} \right)} {\left(\frac{d T}{d y^{\prime}} \right)}_{y^{\prime}=0}}{k_{f} (T_{(y^{\prime}=0)} - T_{b})}. \end{align}$$$$Equation () dimensionless form is given as $$$$\begin{align} C_f &= {\left(1 + \frac{1}{\beta} \right)} {\left(\frac{d U}{d \chi} \right)},\nonumber\\ Nu &= - \frac{{\left(\frac{k_{nf}}{k_{f}} + Rd [(\theta _{h} - 1) \thet...$$…”

Heat transfer analysis of MHD oscillatory SWCNT/MWCNT‐H2O hybrid nanofluid flow in a channel

“…According to the results, boosting the radiation parameter lowers the temperature distribution, while boosting the pressure term raises the velocity distribution. Intending to identify the conditions under which entropy generation and nonlinear heat transfer are minimised, Rosales et al [24] analysed the impact of a magnetic field on couple stress nanofluid in an inclined channel. Using the Runge-Kutta method and a shooting technique, the initial equations were solved.…”

“…Intending to identify the conditions under which entropy generation and nonlinear heat transfer are minimised, Rosales et al. [24] analysed the impact of a magnetic field on couple stress nanofluid in an inclined channel. Using the Runge–Kutta method and a shooting technique, the initial equations were solved.…”

Dual Entropy Regime in Channel Flow Subjected to Temperature Dependent Convection Mechanism

“…where, The local volumetric rate of entropy generation SG for the configuration under study is found as (following the authors in [9,12,13,20,25,33,34])…”