Optimized syngas mixer design for dual‐fuel diesel engines: A <scp>CFD</scp> ‐driven approach to enhance efficiency

Abstract The efficiency of dual‐fuel diesel engines running on syngas is critically dependent on the quality of the air–fuel mixture. This study presents a computational fluid dynamics (CFD) investigation to optimize a syngas mixer design, aiming to enhance mixture homogeneity. Five distinct mixer geometries, including a baseline T‐joint, an extended pipe, a tapered pipe‐tip, and designs with side holes, were systematically evaluated. Using the RNG k ‐ ε turbulence model in ANSYS Fluent, simulations were conducted to analyze pressure distribution, velocity profiles, turbulent kinetic energy (TKE), and the syngas mass fraction uniformity index (UI) at an engine speed of 2000 rpm. The results demonstrate that geometry profoundly influences mixing performance. Model 3, featuring a tapered pipe‐tip, emerged as the optimal configuration, achieving a near‐perfect UI of 0.9997. This superior homogeneity was driven by its ability to generate the highest TKE (21.25 m 2 /s 2 ), which promoted vigorous mixing. However, this design also incurred the largest pressure drop (330 Pa). Model 4 offered a balanced alternative with a high UI (0.9989) and lower pressure loss. All evaluated designs surpassed the performance of conventional compressed natural gas mixers, highlighting the efficacy of geometry optimization for syngas applications. This research provides a validated design pathway for developing highly efficient and sustainable dual‐fuel engine systems.