Thermal Assessment of a Differentially Heated Nanofluid-Filled Cavity Containing an Obstacle

This study focuses on numerically investigating thermal behavior within a differentially heated cavity filled with nanofluid with and without obstacles. Numerical comparison with previous studies proves the consistency and efficacy of the lattice Boltzmann method associated with a single relaxation time and its possibility of studying the nanofluid and heat transfer with high accuracy. Key parameters, including nanoparticle type and concentration, Rayleigh number, fluid basis, and obstacle position and dimension, were examined to identify optimal conditions for enhancing heat transfer quality. Principal findings indicated that increasing the Rayleigh number boosts buoyancy forces and alters vortex structure, improving the heat transfer efficiency across all nanofluid configurations. Moreover, nanoparticles with higher thermal conductivity, particularly Cu nanoparticles, exhibit slight improvements in heat transfer quality compared to Al₂O₃ nanoparticles, while higher nanoparticle concentrations generally lead to enhanced heat transfer effectiveness. Water-Cu nanofluids also demonstrate superior heat transfer performance over ethylene glycol-Cu nanofluids. Furthermore, the presence of obstacles at cavity extremities hampers overall heat transfer, whereas those positioned centrally augment heat exchange rates. This research offers valuable insights into optimizing convective heat transfer in nanofluid-filled cavities crucial for various engineering applications.