Flow and heat transfer of couple stress nanofluid sandwiched between viscous fluids

Abstract

Purpose The purpose of this study is a numerical analysis of steady-state heat transfer behavior of couple-stress nanofluid sandwiched between viscous fluids. It should be noted that this research deals with the development of a cooling system for the electronic devices. Design/methodology/approach Stokes model is used to define the couple-stress fluid and the single-phase nanofluid model is used to define the nanofluid transport processes. The fluids in all regions are assumed to be incompressible, immiscible and the transport properties in all the three layers are assumed to be constant. The governing coupled linear ordinary differential equations are made dimensionless by using appropriate fundamental quantities. The exact solutions obtained for the velocity and temperature fields are evaluated numerically for various model parameters. Findings The results are demonstrated using different types of nanoparticles such as copper, silver, silicon oxide (SiO2), titanium oxide (TiO2) and diamond. The investigations are carried out using copper–water nanofluid for different values of couple-stress parameter a with a range of 0 = a = 12, solid volume fraction ϕ with a range of 0.0 ≤ ϕ ≤ 0.05, Eckert number Ec with a range of 0.001 ≤ Ec ≤ 6 and Prandtl number Pr with a range of 0.001 ≤ Pr ≤ 6. It was found that the Nusselt number increases by increasing the couple stress parameter, Eckert number and Prandtl number and it decreases with a growth of the solid volume fraction parameter. It was also observed that using SiO2–water nanofluid, the optimal Nusselt number is obtained. Further, using copper, silver, diamond and TiO2, nanoparticles and water as a base fluid does not show any significant changes in the rate of heat transfer. The couple-stress parameter enhances the velocity and temperature fields whereas the solid volume fraction suppresses the flow field for both Newtonian and couple-stress fluid. Originality/value The originality of this work is to analyze the heat transfer behavior of couple-stress nanofluid sandwiched between viscous fluids. The results would benefit scientists and engineers to become familiar with the analysis of convective heat transfer and flow structures in nanofluids and the way to predict the heat transfer rate in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors, electronics, etc.

Numerical Study of Mixed Convective Flow of a Couple Stress Fluid in a Vertical Channel with First Order Chemical Reaction and Heat Generation/Absorption

“…Using the equation 13we obtain the dimensionless Nusselt numbers and Sherwood numbers in the form conditions are used solve (17). These are obtained using (5).…”

“…Umavathi [4] has considered free flow of couple stress fluid which is also electrically conducting in a vertical channel. Umavathi et al [5] have investigated the heat transfer of two fluids such as viscous and couple stress fluids in a vertical channel. The poiseuille flow of couple stress fluid with blood flow applications is studied by Valanis et al [6] The effect of viscous dissipation on fully developed mixed convection is analyzed for the laminar flow in a parallel plate vertical channel whose walls exchange heat with an external fluid, with third kind boundary conditions has been studied by E. Zanchini [7].…”

Effects of non‐Darcian and temperature dependent heat source on two‐phase flow in a vertical porous space with thermal radiation

“…(see Refs. ). The problem of two‐phase fluid flow with uniform magnetic field in the presence of temperature dependent heat source was analytically examined by Muthuraj and Srinivas .…”

Pulsating flow of electrically conducting couple stress nanofluid in a channel with ohmic dissipation and thermal radiation – Dynamics of blood

“…Ghosh et al 43 depicted the couple stress and non-linear thermal radiation effects on nanofluid flow over an extended surface by considering magnetite–water nanofluid. Umavathi and Sheremet 44 highlighted the fully developed flow of the couple stress nanofluid sandwiched between viscous fluids by taking silver, copper, titanium oxide, silicon oxide and diamond as nanoparticles. Ramesh et al 45 made a theoretical investigation on mixed electrokinetic and pressure-driven flow of couple stress fluid in a microchannel.…”