Heat transfer in a conical gap using H2O-Cu nanofluid and porous media. Effects of the main physical parameters

Heat transfer around a conical antenna is quantified in this work. Cooling of this active electronic component is ensured by a medium of high porosity saturated by a H2O-Cu nanofluid with a volume fraction varying between 0% and 5%. The ratio between the thermal conductivity of the porous materials and that of the water (base fluid) ranges from 4 to 41.2, the null value corre-sponding to a heat transfer without porous media (only nanofluid). The conical enclosure's aspect ratio varies in the 0.2-0.6 range, being its base inclined between 0 degrees (horizontal base with cone's top oriented upwards) and 180 degrees range (horizontal base with cone's top oriented downwards). The associated Rayleigh number varies within the 3.32x105-6.74x107 range. Heat transfer by natural convection is quantified for any configuration combining these five parameters and presented via a correlation allowing determination of the average Nusselt number. This study shows that heat transfer increases when the cone is tilted. For a given aspect ratio, the maximum is reached when the cone is vertical with the top pointing down. This observation remains valid in the overall Rayleigh number range. The average Nusselt number enhancement varies between 20 and 70%, according on the considered cavity's aspect ratio. This study complements a recent one restricted to the case of a cone whose horizontal base is located at the bottom, being 0.2 the aspect ratio of the enclosure.

Automated summary

The study quantifies heat transfer around a conical antenna using a H2O-Cu nanofluid saturated by a highly porous medium. The thermal conductivity ratio of the porous materials to water ranges from 4 to 41.2. The conical enclosure's aspect ratio and base inclination angle are varied to investigate their effects on heat transfer. A correlation is provided to determine the average Nusselt number. The results show that heat transfer is enhanced when the cone is tilted, reaching maximum when it is vertical with the top pointing down.