بررسي عددي اثر زمان پاشش و زاويه پاشش بر نرخ تبخير سوخت و آلاينده هاي يك موتور بنزيني پاشش چندنقطه اي

Numerical Study of Injection Time and Injection Angle Effects on Rate of Fuel Evaporation and Emission of a Multi-point Injection Gasoline Engine

Carburetor is replaced with port fuel injection systems for reduction of fuel consumption and exhaust emissions. These engines must be optimized for less exhaust emission and fuel consumption for serious emission regulations. In this paper, the effect of injection time and injection angle on the rate of fuel evaporation and emissions in the EF-7 engine has been studied, using KIVA-3V software for improvement of mixing formation process. The results show that fuel injection delay time reduces and directs injection to hot points (such as top face of valve) increasing the rate of fuel evaporation. Injection with 57 degree angle improvs the quality of mixture and combustion resulting in reduction of HC and CO emissions and some increase in NO emission. Other methods, such as spark ignition time adjustment, must be used for reducing NO emission.