Investigation of Trapezoidal Baffle Configurations for Enhanced Heat Transfer and Turbulent Flow Efficiency in Rectangular Channels

This study presents a high-fidelity numerical investigation into the enhancement of turbulent heat transfer and flow characteristics within a rectangular channel equipped with novel trapezoidal diversion plates. The research systematically evaluates the impact of baffle count and geometry on thermal-hydraulic performance at a high Reynolds number of 87,300. A critical contribution of this work is the comprehensive performance assessment of five turbulence models: Standard k-ε, Standard k-ω, SST k-ω, Spalart–Allmaras, and Reynolds Stress Model (RSM). Validation against experimental data reveals that the RSM and SST k-ω models demonstrate superior predictive accuracy in capturing complex flow physics, with a maximum velocity deviation of only 3.8%. Quantitative findings indicate that increasing the number of trapezoidal baffles induces a jet-like flow acceleration, reaching peak velocities of 13.8 m/s (a 77% increase over inlet velocity) and intensifying turbulence-driven mixing. This structural modification results in a significant increase in the Nusselt number, ranging from 14% to 22% compared to standard configurations. The results fill a prominent gap in literature by providing precise numerical data on the synergy between trapezoidal geometries and second-moment closure models, offering a robust framework for the design of next-generation industrial heat exchangers.