Thermal behavior of a conical antenna cooled with nanofluid saturated porous media: effects of the cavity’s inclination and aspect ratio

Abstract

Purpose The aim of this work is to determine the average surface temperature of a conical antenna. Its cooling is ensured by means of a nanofluid-saturated porous structure. The volume fraction of the H2O–Cu nanofluid ranges between 0% (pure water) and 5%, whereas the ratio between the thermal conductivity of the used porous materials and that of water (fluid base) varies in the wide 4–41.2 range. The antenna is contained in a coaxial conical closed cavity with a variable distance between the cones, leading to an aspect ratio varying between 0.2 and 0.6. The axis of the assembly is also inclined with respect to the gravity field by an angle varying between 0° (a vertical axis with top of the cone oriented upwards) and 180° (a vertical axis with top of the cone oriented downwards). Design/methodology/approach Simulations have been done by means of the volume control method based on the SIMPLE algorithm. Findings Results of the numerical approach show that the cavity’s aspect ratio and inclination with respect to the gravity field significantly affect the thermal behavior of the active cone. Otherwise, the work confirms that the Maxwell and Brinkman models used to determine the nanofluid’s effective thermal conductivity and viscosity, respectively, are adapted to the considered assembly. Originality/value A new correlation is proposed, allowing the determination of the average surface temperature of the active cone and its correct thermal sizing. This correlation could be used in various engineering fields, including electronics, examined in the present study.