Research on characteristics of intake flow under supercharging condition in diesel engine

Ample intake charge and suitable intake flow motion can improve the combustion quality in diesel engine for it can promote the mixing process between air and fuel. But enough air charge is more difficult to reach for high blower engine. The stead flow test method under naturally aspirated condition is usually used to obtain the flow characteristics of engine intake port. But it may over-evaluate the flow ability when the intake port is used for a high blower engine. The characteristics of intake flow under supercharging condition have rarely been studied in past. Therefore, it is necessary to make study on the relation between the supercharging pressure and intake flow characteristics for supercharging diesel engine. In this paper, the authors have completed experiments under supercharging condition. The test data showed that the flow coefficient and swirl ratio is reduced with pressure difference increase between inlet and outlet of the port, and the flow coefficient and swirl ratio increases with intake pressure increase.