Search

The flow characteristics and pressure distribution of air flow that is turbulent though a channel of rectangular cross section that fitted with three different configuration arrangements of solid vertical baffle plates are the main topics of this study's numerical analysis. The method of finite volume is utilized to solve two-dimensional differential equations in the analysis. The turbulence dynamics are elucidated by the k-e turbulence model, which is applied in Fluent software. This simulation employed the Finite Volume Method with the SIMPLE algorithm. To thoroughly assess the system, boundary conditions were changed, including the entrance velocity field. The objective of this research is to study the effects of three different configurations of solid vertical baffles in a rectangular duct at a constant Reynolds number of 52,000 on turbulent kinetic energy, pressure drop, temperature variation, friction coefficient, velocity profile, and thermal enhancement factor. In the current model, there are three different arrangements of the solid vertical baffles. Case (1) where there are only two vertical baffles; one is situated at each wall of the channel with height of 0.08 m. In case (2), each baffle is replaced by two ones. So, there are two baffles at the top and bottom surfaces of the duct each has height of 0.04 m with total height of 0.08 m. By keeping the same approach, each baffle in case (2) is replaced by two ones with a height of 0.02 m with total height of 0.08 m, case (3), where there are four baffles at the upper and lower walls of the channel. The model's validity was confirmed using experimental data showing excellent comparability. The main purpose of the research is to study the effects of these configurations on turbulent kinetic energy, pressure drop, temperature variation, friction coefficient, velocity profile, and the factor of thermal enhancement. The Reynolds number is kept constant at 52,000. According to the current study, installing vertical baffles improves mixing. In case (1), maximal axial velocities are obtained in the channel's center; in case (2), they are found above and below the top and bottom baffles. There are several recirculation zones visible at crucial positions, including behind, above, and below the baffles. Case (2) had a thermal enhancement factor maximum of 1.39. Thus, four vertical solid baffles of 0.04 m in height are utilized to optimize this system, two of which are positioned at the top and bottom walls of the channel. [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]