Numerical Analysis and Experimental Validation of Turbulent Flow in Complex Duct Systems

Abstract

Turbulent flow in duct systems presents significant challenges in mechanical engineering applications, particularly in HVAC, automotive cooling, and industrial process systems. This paper investigates the fluid dynamics of turbulent air flow through complex duct geometries using both Computational Fluid Dynamics (CFD) simulations and experimental measurements. The study employs the Reynolds-Averaged Navier-Stokes (RANS) equations with various turbulence models such as k-? and k-? SST, aiming to capture the effects of flow separation, reattachment, and pressure drop across curved and branched duct segments. A prototype duct system is fabricated with multiple bends and obstacles, equipped with pressure taps and anemometers for detailed experimental data acquisition. Simulated flow parameters such as velocity profiles, turbulence intensity, and wall shear stress are compared against experimental results under different operating conditions. The results indicate that the k-? SST turbulence model provides the closest match to the experimental data, although discrepancies remain at high Reynolds numbers. The impact of geometric parameters, including bend radius and crosssectional area variations, on flow characteristics and pressure losses is analyzed. The findings have important implications for improving duct system efficiency and minimizing energy losses.

KEYWORDS: Turbulent Flow, CFD Simulation, Duct Geometry, Experimental Validation, Pressure Drop