Comparative Analysis of Engine Performance and Emissions Using Experimental and GT-POWER Simulation

Abstract

Internal combustion engines' performance and emission characteristics are critical for improving efficiency and environmental sustainability. This study aims to validate the predictive accuracy of GT-POWER simulation software by comparing it with experimental data across multiple engine parameters, including brake efficiency, brake power, brake torque, specific CO and CO₂ emissions, and in-cylinder heat transfer. The engine was tested at various speeds ranging from 1000 to 6000 rpm, and simulation data were generated using GT-POWER under equivalent conditions. Experimental results showed that the maximum brake efficiency occurred at 2000 rpm, reaching 27.3%, while the GT-POWER simulation predicted 26.3%. The peak brake power was 87 kW (experiment) and 84 kW (simulation) at 1600 rpm. Brake torque peaked at 71 bar (experiment) and 66 bar (simulation) at 2000 rpm. Emission results indicated a decrease in brake-specific CO from 75 g/kW·h at 1000 rpm to 21 g/kW·h (experiment) and 16 g/kW·h (simulation) at 6000 rpm. Similarly, CO₂ emissions dropped from 60 g/kW·h to 15 g/kW·h (experiment) and 14 g/kW·h (simulation). In-cylinder heat transfer showed a maximum of 43 kW (experiment) and 38 kW (simulation), with the most significant discrepancies at higher engine speeds. The novelty of this study lies in its multi-variable validation approach and inclusion of thermal behaviour through in-cylinder heat transfer analysis, which is rarely addressed in simulation studies. The results confirm that GT-POWER accurately captures performance trends, particularly within the 1600–2000 rpm range, though refinements are needed for thermal modelling at high speeds.