The thermal behavior and fluid dynamics of Nano-Enhanced Phase Change Materials (NEPCM) in enclosed systems have been investigated using numerical simulations, focusing on the effects of time-varying temperature profiles and nanoparticle concentration. The analysis reveals that the inclusion of nanoparticles significantly enhances the fluid flow velocity and streamlining within the enclosure, particularly for aluminium oxide (Al₂O₃), copper oxide (CuO), and zinc oxide (ZnO) nanoparticles. The results indicate that an increase in nanoparticle concentration leads to an acceleration in fluid flow and improved heat transfer efficiency, with distinct phase change dynamics observed across different concentrations. The study demonstrates that nanomaterials hold substantial potential for enhancing the thermal performance of NEPCM systems. These enhancements can contribute to greater efficiency in thermal energy storage (TES) and heat transfer processes, particularly in industrial applications requiring energy optimization. The findings align with previous research, emphasizing the positive correlation between nanoparticle concentration and velocity streamlining. This work provides valuable insights for the future exploration of different nanoparticle types and concentrations, paving the way for the development of more efficient NEPCM systems in advanced thermal systems.

To investigate the variation in the diffusion patterns of natural gas leaks in the Floating Production Storage and Offloading (FPSO) system, with the aim of formulating appropriate emergency response strategies and minimizing accident losses, a study was conducted on the gas leak issues of oil and gas processing equipment in the FPSO upper module. A consequence prediction and assessment model was established based on Computational Fluid Dynamics (CFD) methods. Sixteen working conditions and one control working condition were developed to simulate the diffusion characteristics of combustible gas leaks. The simulations provided insights into the gas leakage patterns under different conditions and identified the most hazardous scenario for gas leaks in the FPSO upper module. The results indicate that the density and shape of the equipment within the upper module significantly influence the diffusion outcome. After a leak, high concentrations of combustible gas were observed near the crude oil heat exchanger skid in Industrial Zone II. The effects of individual factors on gas diffusion were significant, and the interactions among multiple factors were complex. Wind speed had a more pronounced effect on longitudinal gas diffusion compared to wind direction and leak aperture, while wind direction significantly influenced lateral gas diffusion. The leak aperture, on the other hand, had a more substantial impact on vertical gas diffusion.

Water-cooled heat sinks are efficient cooling solutions for high-heat dissipation applications in industrial and electronic systems. This study investigates water-cooled heat sinks' thermal and hydrodynamic performance through Computational Fluid Dynamics (CFD) simulations. The fluid flow distribution, heat transfer characteristics, and thermal efficiency of various cooling channel geometries were examined under controlled conditions, including a mass flow rate of 0.05 kg/s, an inlet fluid temperature of 22℃, and a convection film coefficient of 80 W/m²℃ between the fluid and heat sink. Additionally, the convection coefficient between the heat sink body and its fins to the environment was set at 10 W/m²℃, with an ambient temperature of 22℃ and a heat flux of 10,000 W/m² applied to the heat sink's base. The analysis reveals that the coolant channel geometry, flow velocity, and the materials' thermophysical properties strongly influence the system's thermal performance and pressure drop. The optimized channel configuration significantly enhanced the heat dissipation efficiency, achieving an increase of 49.1% and a temperature reduction of 59℃. Furthermore, a thermal efficiency of 40.97% and an overall system efficiency of 45.04% were attained. These findings highlight the substantial role of optimized channel geometries in enhancing the performance of water-cooled heat sinks, leading to more efficient and effective cooling systems. The study demonstrates that CFD simulations can be a powerful tool in identifying key design parameters that maximize heat transfer efficiency in water-cooled heat sinks.