| As the environmental problems have been increasingly serious and people’s awareness of environmental protection has been strengthened,the state has implemented stricter and stricter regulations on emissions and fuel consumption.The gas motion in the cylinder of the internal combustion engine has a decisive influence on the formation and combustion of the mixture,and then affects the engine’s power,economy,combustion noise and exhaust emissions.Therefore,the well organized cylinder gas motion plays an important role in improving the flame propagation rate,reducing the cyclical fluctuation of combustion and decreasing the generation of hazardous substances.The numerical simulation of in-cylinder flow field and the related experimental research are carried out based on the 1E65 FM engine.In this paper,the geometric model of 1E65 FM engine is meshed by ANSYS ICEM CFD,and the hybrid mesh method is used to simplify the grid,and to ensure the quality.The mesh system is imported into Fluent for numerical simulation.And the simulation results show that,it formed loop scavenging in the cylinder because of the angle of the scavenging port.The loop scavenging developed into a large scale anticlockwise vortex as the exhaust port closed,and it maintained to TDC.Besides,the vortex scale will be greater without spark plug.The development trend of in-cylinder gas velocity and the turbulent kinetic energy is similar.They maintain a larger value as the scavenging port or exhaust port open,but the turbulent kinetic energy fluctuation is more volatile and complex.When the scavenging port and exhaust port are closed,the in-cylinder gas velocity and turbulent kinetic energy are greatly reduced,and the trend is more relaxed.In this paper,an optical engine experimental platform has been designed and builded based on visual transformation of the 1E65 FM engine,which includs the optical engine,high-speed photography system and schlieren system.Through the experiment platform,successfully captured the images of jump-spark,flame and flow field.And collected speed and pressure signal synchronized with the photographic image,which verifies the validity and reliability of the optical engine experimental platform.And the test results coincide with the simulation results. |
