Study on the Effect of the Intake Port Configuration on the In-cylinder of Small Engine

Abstract

The airflow in the engine cylinder is known to greatly affect the performance of the engine. Therefore, the main objective of this study is to evaluate the flow characteristics of the in-cylinder small engine to see the effect of the intake port configuration at equivalent rated engine speed using simulation model under various intake valve lift conditions. Geometry engine created using CAD software, then exported and analyzed using CONVERGE. The turbulence model is observed using a modified model (RNG) k-ɛ. The pressure boundary conditions are used to determine the pressure fluid at the intake and exhaust port. The result shows that the change combination of the intake port give effect to swirl ratio value. The helical intake port with same direction have the highest swirl ratio during intake and compression stroke around thirteen times compare to the original model in valve lift maximum. The change combination of the intake port also give effect to the tumble ratio where the maximum tumble ratio occurs at the helical port with same direction where the maximum increase at 460 °CA around 83 % and the minimum tumble ratio occurs at helical port with opposite direction where the maximum decrease at 460 °CA around 83 %. The change combination of the intake port also give effect to increase the turbulent kinetic energy where the maximum increase around 300 % for model with same direction and 240 % for model with opposite direction and length scale also increase 35 % for model with same direction and 40 % for model with opposite direction. Finally, it is concluding that the analysis carried in this work is useful in predicting the flow and in-turn optimizing combustion chamber of the engine.