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The turbulent airflow in a rectangular channel with two porous vertical baffles of 25%, 50%, and 75% porosity is investigated using the finite volume method and Fluent software. The k-ε turbulence model analyzes turbulence dynamics, adjusting boundary conditions for varying inlet velocities. Key parameters, including turbulent kinetic energy (TKE), dynamic pressure (DP), temperature variation (T), friction coefficient (Cf), Nusselt number (Nu), and thermal enhancement factor (TEF) are evaluated at Reynolds numbers of 28,000 and 56,000. Findings indicate that at a Reynolds number of 28,000, the 25% porous ratio maximizes energy transfer, while the friction coefficient peaks at the same ratio for a Reynolds number of 56,000. Notably, the TEF reaches 1.4 at a 75% porous ratio for a Reynolds number of 28,000. This research uniquely demonstrates the pronounced impact of porous baffles on heat transfer and friction under different Reynolds numbers, particularly highlighting the significance of baffle porosity in lower Reynolds number regimes. [ABSTRACT FROM AUTHOR]

This study presents a numerical analysis of turbulent air flow through a rectangular duct fitted with two perforated vertical baffle plates, focusing on flow characteristics and pressure distribution. The analysis employs two-dimensional differential equations, solved using the finite volume method. The k-e turbulence model, implemented in Fluent software, elucidates the turbulence dynamics. Boundary conditions, including the entrance velocity field and exit atmospheric pressure, were varied to comprehensively evaluate the system. The model's validity was established against experimental data at a Reynolds (Re) number of 87300, demonstrating excellent comparability at a distance of 0.525 m from the duct entrance. The research aims to investigate the effects of different Re numbers (10,000, 20,000, and 30,000) on various parameters in a duct equipped with two perforated, nozzleshaped vertical baffles, each comprising eight trapezoidal sections forming seven nozzles. Parameters analyzed include the velocity profile, pressure drop, turbulent kinetic energy, dynamic pressure coefficient, and skin friction coefficient. The study finds that the insertion of perforated vertical baffles enhances mixing, particularly at higher Re numbers. Axial velocities attain maximum values above the bottom baffle and below the top baffle, with multiple re-circulation zones observed at strategic locations including above, below, and behind the baffles. Significant findings include the occurrence of maximum vertical velocity values at Re=30000 upstream of the bottom baffle, and a substantial re-circulation zone immediately upstream of the upper baffle. The channel's thermal enhancement factor is noted to improve with decreasing levels of skin friction as the Re number increases. Pressure values rise at the junctions where the duct's inner walls meet the upper surfaces of the baffles. Turbulent kinetic energy across the duct is categorized into three distinct zones based on the Re number: Zone 1, between the entry and the first baffle, exhibits minimal turbulence influence; Zone 2, located between the baffles, shows a peak turbulent kinetic energy of about 3 m²/s² near the nozzle exits and the bottom of the top baffle; Zone 3, extending from the second baffle to the outlet, records the highest turbulent kinetic energy rate at a Re number of 30,000. [ABSTRACT FROM AUTHOR]