Cfd Analysis Based On The Engine Intake Valve Actuator

An electromagnetic actuated valvetrain(EMVA) has been developed based on a moving coil electromagnetic linear actuator. Cancelling the throttle and using the variable valve technology to control the load and the quality of the cylinder gas, you do not need to reduce the inlet pressure, avoided pumping losses and achieved load control without the throttle.But the variable valve that eliminated the throttle has a great impact on the cylinder working gas,the comparison of cylinder flow field between between cam-driving and Electromagnetic valve actuator is still blank.The cylinder flow field has a major impact on the mixing, combustion quality, Emissions of harmful gases and so on. The cylinder flow field is transient, and it is subject to engine size, speed, load, valve timing and lift. So the accurate evaluation of the cylinder flow field and gas movement intensity has been a hot research of the home and abroad scholars. The main contents include the following:Based on a four-valve gasoline engine intake system CFD example and foreign related research progress, analyzed the deficiency of Tumble ratio and Swirl ratio as engine gas movement intensity measurement. For the analysis of the steady-state CFD, proposed unit mass kinetic energy and turbulent kinetic energy flow rate through valve channel surface to evaluate macroscopic and microscopic gas movement intensity. For intake and compression process transient CFD analysis, proposed in-cylinder unit mass kinetic energy and turbulent kinetic energy to evaluate macroscopic and microcosmic gas movement intensity.Using computational fluid dynamics software FLUENT five-valve model static simulations were carried on,compared the cylinder flow field and movement intensity of gas, verified the reliability of the new evaluation parameters. Obtained that the small valve lift can improve the movement intensity of gas.Under a low speed and part load condition,3D transient numerical simulation of intake process was carried on. Simulation results reveal that EMVA responsed quickly and reached the maximum valve lift in 4ms, which improved the volumetric efficiency. The inlet pressure of EMVA was closed to the atmospheric pressure, and greatly reduced the pumping loss. The movement intensity of gas in cylinder of EMVA is better than that cam-driving.