thehienoto
Thành viên O-H
Màng nhiên liệu mỏng này này ở trên lỗ xu páp nạp ở vùng tiếp giáp đế xupap. Bác nên nhớ làvơi động cơ lúc khởi động sẽ phun đậm nhất, lại phun trên đường nạp , máy lại nguội nên nhiên liệu sẽ bám trên thành lỗ xupap nạp.
nhờ bác xem dùm em cụm mà em đánh dấu thì nên dịch ntn là hợp lý được không bác!
Alternatively, injecting fuel directly into the engine cylinder totally avoids the problems associated with fuel wall wetting in the port, while providing enhanced control of the metered fuel for each combustion event, as well as a reduction in the fuel transport time. The actual mass of fuel entering the cylinder on a given cycle can thus be more accurately controlled with direct injection than with PFI. The GDI engine offers the potential for leaner combustion, less cylinder-to-cylinder variation in the air-fuel ratio and lower operating BSFC values. The UBHC emissions during a cold start are also potentially lower with direct injection, and the engine transient response can be enhanced. As a result of the higher operating fuel pressure of the GDI system, the fuel entering the cylinder is much better atomized than that of the PFI system, particularly under cold operating conditions, thus yielding much higher rates of fuel vaporization. The mean drop size is typically 16 microns SMD as compared to 120 microns SMD with the PFI system. It is important to note, however, that injection of fuel directly into the cylinder is not a guarantee that fuel film problems are not present. The wetting of piston crowns or other combustion chamber surfaces, whether intentional or unintentional, does introduce the important variable of transient wall film formation and evaporation.