Rectangular heat sink filled with PCM/ hybrid nanoparticles composites and cooled by intruded T-shaped cavity: Numerical investigation of thermal performance

The thermal storage efficiency of the ice within a rectangular system, which is charged from three sides and is cooled by an intruded T-shaped cavity, is low. It is due to the low thermal conductivity of the ice. The use of metallic nanoparticles inside ice to boost the thermal diffusion is limited due to the stability and chemical reaction. To remove this shortcoming, water-based hybrid nanofluids (NFs), which possess a lower thermal conductivity with inertness, have been used. In this study, the influences of the inclination angle and hybrid nanopowders, Ag 25 nm-MgO 40 nm (50:50 weight proportion), Al2O3-Cu 17 nm (90:10) and SiO2-MWCNT 10 nm (50:50) with the volumetric concentration <= 0.02 on the evolution of the convection-controlled melting in this novel thermal energy storage unit have been evaluated. An iterative explicit enthalpy-based double distribution function-lattice Boltzmann model within the single-phase framework has been applied where there is the thermal equilibrium condition between solid NPs and the base PCM. It is revealed that silica-MWCNT NPs/water composite with a volume fraction of 0.01 inside the case (I) is the best configuration to obtain the least melting time with a higher thermal storage capacity despite the high price of NPs.