A Numerical Study on the Transient Injection Characteristics of Gas Fuel Injection Devices for Direct-Injection Engines

Natural gas has emerged as one of the preferred alternative fuels for vehicles owing to its advantages abundant reserves, cleaner combustion and lower cost. At present, supply methods natural-gas engines are mainly port fuel injection (PFI) direct (DI). The transient characteristics a device, terminal executive component PFI or DI mode, will directly affect key performance engine. Therefore, devices have been selected research object this paper, with focus on process. To explore impacts valve vibration amplitude, period, frequency velocity characteristics, computational fluid dynamics (CFD) model was established. findings thereof demonstrated that there is linear relationship between instantaneous mass flow rate lift during However, somewhat impacted when speed high enough. A shorter period tends preclude flow-hysteresis fluctuation. near-field pressure fluctuation at throat an caused by vibration, initiates