Experimental Study of the In-Cylinder Swirl Characteristics of a Four-Valve Gasoline Engine With Variable Inclined Swirl System

The variable inclined swirl system of a four-valve gasoline engine was developed.The effects of the system on intake flow characteristics and swirl characteristics of a four-valve engine were measured on a steady flow rig.The results show that at any angle between the axis of inclined swirl control valve and that of crank,the flow coefficient decreases while the valve opens.The maximum flow coefficient is 0.82 when valve opens 0.The flow coefficient is variable between 0.13 and 0.82.The maximum swirl at the end of induction stroke is 0.11 when the angle between the axis of inclined swirl control valve and that of crank is 30 and the valve opens 45.The swirl ratio at the end of induction stroke is variable between 0.01 and 0.11.