Nano-particle characteristics were investigated in the gasoline direct injection engine, for various air fuel ratios, fuel pressures and fuel injection timings in the part load condition. PN concentration and size distribution were measured by the DMS...
Nano-particle characteristics were investigated in the gasoline direct injection engine, for various air fuel ratios, fuel pressures and fuel injection timings in the part load condition. PN concentration and size distribution were measured by the DMS-500 equipped upstream of catalyst. Nano particle emission was closely related with fuel injection timing and in-cylinder flow motion in GDI engine. As a result, PN was decreased with increasing air fuel ratio and fuel pressure. And fuel injection timing was retarded over the middle intake stroke, particle emission was increased but reduced PN during the early intake stroke. In conclusion, optimization of the ECU control strategy on the fuel injection pressure, injection timing as well as air fuel ratio was needed to improve the nano particle emissions in GDI engine.