Numerical design of a new LPG-fueled opposed piston engine

In this study, a new liquefied petroleum gas (LPG)-fueled Opposed-Piston Two-Stroke (OP2S) engine was numerically designed and analyzed using Computational Fluid Dynamics (CFD) simulations coupled with a developed reduced chemical kinetics mechanism. The combustion characteristics of LPG were compared to those of gasoline in terms of in-cylinder pressure, mean temperature, and emission formations. The results indicated that LPG is a promising alternative to gasoline, reducing CO2 and NOx emissions by approximately 18 % and 8 %, respectively. Engine performance of a LPG-fueled OP2S engine was evaluated across a range of engine speeds and loads, revealing maximum indicated thermal efficiencies of 37.1 % and 40.9 % at full and part loads, respectively. Optimal NOx reduction was achieved when the peak in-cylinder pressure occurred between + 11 CA and + 13 CA after top dead center. Furthermore, it was seen that the trapped mass quantity increased by about 2.3 % for every 1000 rpm increase in engine speed, stabilizing beyond 5000 rpm. Overall, the findings demonstrate the potential of LPG-fueled OP2S engines to deliver high efficiency and reduced emissions, supporting their viability for future sustainable transportation applications.