Finite element analysis of micropolar nanofluid flow through an inclined microchannel with thermal radiation

Abstract

PurposeIn recent years, microfluidics has turned into a very important region of research because of its wide range of applications such as microheat exchanger, micromixers fuel cells, cooling systems for microelectronic devices, micropumps and microturbines. Therefore, in this paper, micropolar nanofluid flow through an inclined microchannel is numerically investigated in the presence of convective boundary conditions. Heat transport of fluid includes radiative heat, viscous and Joule heating phenomena.Design/methodology/approachGoverning equations are nondimensionalized by using suitable dimensionless variables. The relevant dimensionless ordinary differential systems are solved by using variational finite element method. Detailed computations are done for velocity, microrotation and temperature functions. The influence of various parameters on entropy generation and the Bejan number is displayed and discussed.FindingsIt is established that the entropy generation rate increased with both Grashof number and Eckert number, while it decreased with nanoparticle volume fraction and material parameter. Temperature is decreased by increasing the volume fraction of Ag nanoparticle dispersed in water.Originality/valueAccording to the literature survey and the best of the author’s knowledge, no similar studies have been executed on micropolar nanofluid flow through an inclined microchannel with effect of viscous dissipation, Joule heating and thermal radiation.

Irreversibility analysis of micropolar nanofluid flow using Darcy–Forchheimer rule in an inclined microchannel with multiple slip effects

“…The thermophysical properties of nanoparticles and base fluid are given in Table 1. Table 2 represents a comparison of results between the present study and those from a previously published article by Shashikumar et al 4 The effects of thermal radiation Rd ( ) on microrotation, temperature profile, entropy generation, and Bejan number are observed in Figure 2A-C. Figure 2A explained the increment in the value of Rd with increment in temperature profile because of radiative heat flux and interaction of thermal boundary layer with radiation.…”

“…Under the above presumption, the governing equations of the momentum, microrotation, energy, entropy generation, and Bejan number are as follows 4,37 : $$${\rho }_{\mathrm{nf}}{\nu }_{0}\frac{du{^{\prime} }}{dy{^{\prime} }}=-\frac{{dp}}{{dx}{^{\prime} }}+({\mu }_{\mathrm{nf}}+q)\frac{{d}^{2}u^{\prime} }{dy{{\prime} }^{2}}+q\frac{dN^{\prime} }{dy^{\prime} }-{\sigma }_{\mathrm{nf}}{B}_{0}^{2}u^{\prime} +({\rho \beta )}_{\mathrm{nf}}g* (T^{\prime} -{T}_{a}^{^{\prime} })\mathrm{sin\lambda }-\frac{{\mu }_{\mathrm{nf}}}{L}u^{\prime} -{\rho }_{\mathrm{nf}}\frac{F{u^{\prime} }^{2}}{\surd L},$$$ $$${\rho }_{\mathrm{nf}}{j\nu }_{0}\frac{dN{^{\prime} }}{dy{^{\prime} }}={\eta }_{\mathrm{nf}}\frac{{d}^{2}N^{\prime} }{d{y^{\prime} }^{2}}-q\left(2N^{\prime} +\frac{du^{\prime} }{dy^{\prime} }\right),$$$ …”

“…By assuming Rosseland's flux model, the thermal radiative heat flux is taken as, 4,25 $$${q}_{r}=-\frac{4\sigma * {dT^{\prime} }^{4}}{3k* dY^{\prime} },$$$where $$k* $$ is the mean absorption coefficient of the nanofluid and $$\sigma * $$ is the Stefan–Boltzmann constant. Furthermore, using Taylor series expansion, we explained the temperature difference within the flow.…”

“…The fluid injection takes place at the bottom plate y a ′ = − and suction takes place at the upper plate y a ′ = . Under the above presumption, the governing equations of the momentum, microrotation, energy, entropy generation, and Bejan number are as follows 4,37 :…”

Scrutinization of thermodynamic second law for the steady flow of couple stress nanofluid in an inclined microchannel by varying thermal conductivity

“…The natural convection flow in a microchannel with magnetic effect and heat production in an oblique microchannel is investigated by Zaidi and Ahmad 20 . The flow of micropolar fluid is accounted by Shashikumar et al 21 to study the flow features. Gireesha and Roja 22 considered the Casson fluid to flow in an oblique microchannel.…”