The present study evaluates the heat transfer performance of an immersion liquid cooling system, utilizing copper-water (Cu-water) nanofluids under various flow and geometric conditions, including different Reynolds and Rayleigh numbers, nanoparticle volume fractions, and block spacing configurations. To this end, numerical simulations were conducted to assess the impact of these parameters on the system’s temperature distribution and overall cooling efficiency. The findings indicate that augmenting the Reynolds number from 100 to 500, and the nanoparticle volume fraction from 0% to 5%, at a Rayleigh number of 10⁵, results in substantial enhancements in heat transfer, with improvements reaching up to 193.8%. Furthermore, an increase in the Rayleigh number from 10³ to 10⁶, in conjunction with elevated nanoparticle concentrations at a Reynolds number of 500, yielded a heat transfer enhancement of up to 36.3%. These findings demonstrate that higher Reynolds and Rayleigh numbers promote better heat dissipation through increased convective flow and buoyancy-driven convection. Furthermore, the study underscores the pivotal function of block spacing in maximizing cooling efficacy. While closer spacing results in higher temperatures, wider spacing improves heat transfer efficiency by reducing thermal interference between blocks. The study emphasizes the synergistic effect of an enhanced thermal conductivity, strong convective flow, and optimal geometric configurations in maximizing cooling efficiency. These findings are of crucial importance for the design of more efficient thermal management systems, with applications in electronics cooling, energy systems, and industrial processes.

This study presents a numerical investigation of fluid flow around a heated rectangular cylinder controlled by an inclined partition, aiming to suppress vortex shedding, reduce aerodynamic drag, and enhance thermal exchange. The double multiple relaxation time lattice Boltzmann method (DMRT-LBM) is employed to investigate the influence of Reynolds number variations and partition positions on the aerodynamic and thermal characteristics of the system. The results reveal the presence of three distinct thermal regimes depending on the Reynolds number. Increasing the Reynolds number intensifies thermal vortex shedding, thereby improving heat exchange efficiency. Moreover, a higher Reynolds number leads to a greater reduction in the drag coefficient, reaching $125.41\%$ for $Re=250$. Additionally, improvements in thermal performance were quantified, with Nusselt number enhancements of $29.47\%$ for $Re=100$, $55.55\%$ for $Re=150, 74.78\%$ for $Re=200$, and $82.87\%$ for $Re=250$. The influence of partition positioning g on the aerodynamic performance was also examined at $Re=150$, revealing that increasing the spacing g generally leads to a rise in the drag coefficient, thereby reducing the percentage of drag reduction. However, the optimal configuration was identified at $g=2d$, where the maximum drag coefficient reduction reached $130.97\%$. In contrast, the impact of g on the thermal performance was examined for $Re=100, 150,$ and $200$, revealing a significant heat transfer improvements on the top and bottom faces: reaching up to $99.47\%$ on the top face for $Re=200$ at $g=3d$. Nevertheless, for all Reynolds numbers and partition placements, a decrease in heat transfer was observed on the front face due to the partition shielding it from the incoming flow. These findings underscore the effectiveness of an inclined partition in enhancing both the thermal and aerodynamic performance of a rectangular component. This approach holds strong potential for various industrial applications, particularly in aeronautics, where similar control surfaces are used to minimize drag, as well as in heat exchangers and electronic cooling systems where optimizing heat dissipation is crucial for performance and energy efficiency.

This paper employs the lattice Boltzmann method to investigate the heat transfer properties of a nanofluid circulating within an open square cavity that contains three heated obstacles. The nanofluid is introduced into the system via a lower inlet and exits the system via an outlet located at the top of the opposite wall, flowing along the cavity walls. The study examines the effects of Reynolds number, nanoparticle size fraction and the orientation of the obstacles on both temperature distribution and the Nusselt number. The results indicate that the horizontal configuration of the barriers markedly enhances heat transfer in comparison to the vertical configuration. Furthermore, an increase in the volume fraction of nanoparticles results in enhanced heat transfer, with improvements of 16.5% for the vertical configuration and 17.5% for the horizontal configuration at a nanoparticle concentration of 5%. It is noteworthy that there is a considerable increase of approximately 152.4% in the Nusselt number when the Reynolds number is increased from 100 to 500. This study highlights the pivotal role of nanoparticle concentration and obstacle orientation in optimising the thermal management of microfluidic devices and electronic cooling systems.