Ahmada Omar Ali, Oluwole Daniel Makinde and Yaw Nkansah-Gyekye
The purpose of this paper is to investigate numerically the unsteady MHD Couette flow and heat transfer of viscous, incompressible and electrically conducting nanofluids between…
Abstract
Purpose
The purpose of this paper is to investigate numerically the unsteady MHD Couette flow and heat transfer of viscous, incompressible and electrically conducting nanofluids between two parallel plates in a rotating channel.
Design/methodology/approach
The nanofluid is set in motion by the combined action of moving upper plate, Coriolis force and the constant pressure gradient. The channel rotates in unison about an axis normal to the plates. The nonlinear governing equations for velocity and heat transfer are obtained and solved numerically using semi-discretization, shooting and collocation (bvp4c) techniques together with Runge-Kutta Fehlberg integration scheme.
Findings
Results show that both magnetic field and rotation rate demonstrate significant effect on velocity and heat transfer profiles in the system with Cu-water nanofluid demonstrating the highest velocity and heat transfer efficiency. These numerical results are in excellent agreements with the results obtained by other methods.
Practical implications
This paper provides a very useful source of information for researchers on the subject of hydromagnetic nanofluid flow in rotating systems.
Originality/value
Couette flow of nanofluid in the presence of applied magnetic field in a rotating channel is investigated.
Details
Keywords
Sara Khamis, Daniel Oluwole Makinde and Yaw Nkansah-Gyekye
The purpose of this paper is to investigate the combined effects of buoyancy force and variable viscosity on unsteady flow and heat transfer of water-based nanofluid containing…
Abstract
Purpose
The purpose of this paper is to investigate the combined effects of buoyancy force and variable viscosity on unsteady flow and heat transfer of water-based nanofluid containing copper and alumina as nanoparticles through a porous pipe.
Design/methodology/approach
Using the Boussinesq and boundary-layer approximations with Buongiorno nanofluid model. The governing nonlinear partial differential equations for the continuity, momentum and energy balance are formulated. The equations obtained are solved numerically using a semi-discretization finite difference method (know) as method of line coupled with Runge-Kutta-Fehlberg integration scheme.
Findings
Numerical results for the skin-friction, heat transfer and for the velocity and temperature profiles are obtained. The results show that with suction, Cu-water produces higher skin friction and heat transfer rate than Al2O3-water. Both nanofluids velocity and temperature increase with a decrease in viscosity and an increase in buoyancy force intensity.
Practical implications
Buoyancy-driven flow and heat transfer in porous geometries has many significant applications in industrial and engineering such as, electrical and microelectronic equipments, solar-collectors, geothermal engineering, petroleum reservoirs, thermal buildings insulation. This work provides very important information for researchers on this subject.
Originality/value
This paper illustrates the effects of buoyancy force and temperature dependent on heat transfer and fluid flow problem using Cu-water and Al2O3-water nanofluids in a porous pipe.