Effect of the helical-spiral shroud intake valve on flow in cylinder of internal combustion engine

Abstract

In this paper, we proposed a method to increase the mixing performance of gasoline and intake air by attaching a helical-spiral shroud to the intake valve. The effect of the height and revolution number of helical-spiral shroud on the generation of swirl in the engine cylinder are analyzed. The height is 20 and 25 mm, and the revolution number is changed to 1 and 1.5 turns. A three-dimensional simulation model using the shear stress transport k–ω model is used as the turbulence model to predict the air flow characteristics through the intake valve and engine cylinder in the intake and compression strokes. As a result, the helical-spiral shroud intake valve (HSSIV) generally increases the swirl ratio compared to the general valve, and the swirl ratio in the HSSIV with a height of 20 mm and revolution number of one turn has a maximum value of 77 around 90CAD. It also shows that HSSIV has little effect on the volumetric efficiency reduction while increasing the swirl ratio from different geometrical properties than the conventional shroud valves.