Abstract The performance and emissions of internal combustion engines remain critical challenges in automotive engineering. This study presents the design, simulation, and validation of a swirl-enhancing ram-effect intake manifold for a single-cylinder compression-ignition (CI) engine, aiming to improve airflow dynamics and fuel-air mixing. A parametric analysis was conducted by varying manifold lengths (70 mm to 120 mm) and draft angles (1.26° to 18°). CFD simulations performed using ANSYS Fluent, validated through experimental testing using a 3D-printed prototype and an anemometer-based setup, revealed that longer intake manifolds and steeper draft angles significantly improved airflow velocity and swirl intensity. Specifically, a 120 mm manifold with an 18° draft angle achieved an outlet velocity of 41 m/s, a 350% increase over the baseline 9.1 m/s at 1.26̊ draft angle, enhancing volumetric efficiency. However, these benefits came with increased pressure drop, which rised from -171 Pa for 50 mm manifold at 1.26˚ to -10028 Pa for the 120 mm manifold at 18̊. Experimental results showed a 6.05% deviation from the simulations, which may caused by surface roughness of the 3D-printed manifold that may induced additional restrictions and unaccounted flow variations that might not be replicated in the simulation environment .However, the study is limited to a single-cylinder engine and does not account for thermal effects, material stresses, or performance under varying load conditions. Future work should extend the analysis to multi-cylinder engines, incorporate thermal and structural effects, and evaluate performance across a wider range of operating conditions and fuel types Overall, the optimised manifold geometry enhanced air induction, reduced mixing inefficiencies and showed strong potential for boosting engine performance and reducing emissions in CI engines. These findings highlight the significance of intake manifold geometry in engine design for achieving both performance and sustainability objectives.
ANAND et al. (Wed,) studied this question.