Impact of Space-Dependent Thermal Conductivity on Heat Transfer in a Vertical Annulus with Asymmetric Surface Heating

Over the past two centuries, thermal conductivity (often denoted k, λ, or κ) is the property of a material to conduct heat. It is evaluated primarily in terms of Fourier’s law for heat conduction. Materials of high thermal conductivity transfer heat faster than materials with lower thermal conductivity. Correspondingly, materials of high thermal conductivity are widely used in heat sink applications and materials of low thermal conductivity are used as thermal insulation. The thermal conductivity of a material may depend on temperature. Thermal conductivity is important in material science research, electronics, building insulation and related fields, especially where high operating temperatures are achieved. The impact of temperature dependent thermal conductivity has been studied over decades and interesting results have been obtained. Prasad et al. [1] studied the effects of variable fluid properties on the hydromagnetic flow and heat transfer over a non-linearly stretching sheet. Later, Animasaun [2] investigated the effect of thermophoresis, variable viscosity and thermal conductivity on free convective heat and mass transfer of non-darcian MHD dissipative casson fluid flow with suction and order of chemical reaction. He concluded that viscosity parameter as well as thermal conductivity parameter decreases fluid temperature. Other works on temperature dependent thermal conductivity can be found in [3-6].