A Study on the Variable Swirl in a 4 Valve High Speed Direct Injection Diesel Engine

According to the correlativity between the swirl ratio and the speed of spray to wall at the end of the compression stroke,a model was established,which is about the relation of spray,profile of chamber and swirl intensity.The optimum swirl ratio to engine speed in a four valve DI engine is estimated.A two inlet port with a swirl control valve is designed.The influence of the area of inlet port on swirl ratio and flow coefficient is investigated on steady flow rig.Experimental results showed that the swirl ratio on a four valve DI engine can be adjusted through the control of swirl control valve.