MHD natural convection in an annular space between two coaxial cylinders partially filled with metal base porous layer saturated by Cu-water nanofluid and subjected to a heat flux

The aim of this study is to better understand the behavior of the nanofluid in a specific configuration, aiding in the creation of new models and designs for heat transfer systems, by investigating the MHD natural convection in an annular partially porous metal space between two vertical concentric cylinders, which is saturated by (Cu-water) nanofluid. The inside cylinder undergoes a regular heat flux, whereas the outer cylinder maintains a uniform temperature. The upper and lower walls are impermeable and insulated. In the upward direction, an exterior magnetic field with constant intensity is used. The nonlinear coupled conservation equations with specified boundary conditions in the vorticity-stream function form are solved using the finites differences method in conjunction with the successive over relaxation method. The numerical results obtained are presented to show the impact of a variety of control parameters depicted in Darcy number 10(-5) <= Da <= 10(-1), Rayleigh number 10(4) <= Ra <= 10(6), Hartmann number 0 <= Ha <= 100, heater size, the porous layer thickness 0.25 <= Xp <= 0.75, and nanoparticle concentration 0.01 <= phi <= 0.05. From this study, the increase in the Ra number from 10(4) to 10(6) causes a thermal energy transmission improvement of 50%. Furthermore, a rise in the Da number from Da = 10(-5) to Da=10(-1) enhances the thermal energy transport by approximately 30%, while it reduces by 4.8% when we increase the Hartmann number from 0 to 100. Also, the rise in nanoparticle concentration leads to an enhancement of the average Nusselt number, while the heat transfer rate is reduced by extending the heater size. The numerical results also show a significant improvement in the thermal energy transport in active walls by using an optimum thickness layer of stainless steel porous medium, according to the Da number. Furthermore, this study demonstrates that there is a critical value of porosity for a given nanoparticle concentration and porous layer thickness for better heat transfer enhancement.

Automated summary

The aim of this study is to investigate the MHD natural convection in an annular partially porous metal space saturated by nanofluid, in order to create new models and designs for heat transfer systems. The numerical results show that various control parameters have a significant impact on heat transfer, and using an optimum thickness layer of stainless steel porous medium can enhance thermal energy transport.