THERMAL PERFORMANCE OF IONANOCOLLOIDS IN A CUBICAL CAVITY WITH INTERNAL PROTRUSIONS

Abstract

Ionic liquids have gained considerable attention as heat transfer fluids due to their unique properties, such as low vapor pressure and high thermal stability, which make them suitable for high-temperature applications. The purpose of this study is to examine the thermal behavior of ionanocolloids in a cubical cavity with an internal protruding heat source. The effect of Brownian motion and turbulence on the flow characteristics and thermal enhancement of ionic liquid dispersed with nanoparticles of silicon dioxide, aluminum oxide, and single-walled carbon nanotubes is investigated. The computations are performed by developing an unsteady, turbulent multiphase mixture model discretized by the finite difference method. The heater aspect ratio (ε), Grashof number (Gr), and nanoparticle volume concentration (φ) are varied in the following ranges, respectively: 0.2 ≤ ε ≤ 5, 10<sup>6</sup> ≤ Gr ≤ 10<sup>10</sup>, and 2% ≤ φ ≤ 6%. It is found that the velocity, kinetic energy, and Nusselt number are increasing functions of the heater aspect ratio and particle concentration. The coalescence of the nanoenhanced ionic liquid mixture is phenomenal for its lower heater aspect ratio. The carbon nanotube-dispersed ionanofluid mixture exhibited superior thermal performance for a turbulent Grashof number and enhanced the average Nusselt number of pure ionic liquid by 141.13%. The multiphase model is validated, and results are closer to the benchmark experimental findings.