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The effectiveness of triangular baffles in enhancing heat transfer within corrugated tubes is examined numerically in this study. Two key parameters influencing performance are examined: baffle placement (staggered and aligned) and their angles of attack (0°, 15°, 30°, and 45°). Heat transfer, friction, as well as performance metrics are comprehensively examined and compared for both configurations. The finite element method (FEM) implemented in CFD software COMSOL Multiphysics 6.1 is employed for simulations across a range of Reynolds numbers (100-400). Results reveal significant heat transfer improvements due to the proposed baffle configurations. Notably, aligned baffles with a 30° angle of attack achieve a 43.6% increase the heat transfer when compared to the baffle-free scenario. Staggered baffles with a 15° angle of attack demonstrate a superior 55.3% improvement compared to the baseline. A comprehensive evaluation of performance criteria identifies staggered baffles with a 30° angle of attack as the optimal configuration for maximizing heat transfer within corrugated tubes. [ABSTRACT FROM AUTHOR]

The study analyzes the unique behavior of two-phase flows when incorporating nanofluids containing aluminum trioxide (Al2O3) and copper (Cu) nanoparticles in a vertical channel. The main goal is to investigate the behavior of airnanofluid mixtures in this setting, with potential implications for industrial and exploration applications. Research in this area could provide valuable insights into the dynamics of these flows and their impact on heat transfer, fluid dynamics, and material science. This study includes an analysis of upwelling dynamics, the effect of fluid characteristics on bubble growth, and the system's thermal efficiency. Using numerical and quantitative visualization techniques, we seek to understand the behavior of these particles at the interface between the liquid and gas phases by integrating Al2O3 and Cu nanoparticles into the VOF approach. Because of their superior thermal conductivity, copper nanoparticles have a higher volumetric density and provide more efficient heat transfer, leading to quick and efficient thermal dissipation. Smaller nanoparticles offer an increased surface area-to-volume ratio, which improves heat transfer capabilities and ensures uniform heat dissipation throughout the material. Consequently, copper nanoparticles emerge as the preferred choice for applications necessitating high thermal transfer and optimal performance. These results significantly impact the design of more efficient heat exchangers and optimize recovery techniques by elucidating the interactions between these nanoparticles and the surrounding fluids. Furthermore, the selection of smaller copper nanoparticles further amplifies thermal transfer, maximizing performance across diverse applications. [ABSTRACT FROM AUTHOR]

In this paper, we suggest a theoretical model for the exchange of the orbital angular momentum (OAM) state of laser fields in a real cold atomic system for realization in an experimental setup. By using four-wave mixing (FWM) processes, we study the spatial dependence of the new weak generated signal light under electromagnetically induced transparency conditions when one of the laser lights becomes an optical vortex. We discuss the spatial dependence of FWM processes via experimental parameters for different conditions of the OAM of vortex light. We have found that the intensity and phase distributions of the new generated light depends strongly on the OAM number of the optical vortex light. Moreover, we investigate the absorption spectrum of the new generated signal light for different OAM of the optical vortex light. Our obtained results may have potential applications in quantum information science. [ABSTRACT FROM AUTHOR]