تجزيه و تحليل نحوه شكل گيري مخلوط سوخت و هوا در موتورهاي بنزيني تزريق مستقيم

Analysis of Air Fuel Mixture Formation in Gasoline Direct Injection SI Engines

In gasoline direct injection SI engines, fuel is directly injected into the cylinders. Proper air fuel mixture formation in cylinder gives a potential of reducing specific fuel consumption and exhaust emission. Short fuel injection timing and mixture formation in addition to complexity of fluid dynamics in cylinder for a wide range of" engine speed and load, causes a major difference with what happens to air and fuel mixture formation and combustion behavior in a multi port fuel injection or carburetion system engine. In this research, a method to model the air fuel mixture formation by combining the mixture formation parameters such as fuel pressure, injection duration, injection velocity and injector location in combustion chambers has been presented and developed. This study has been carried out from fuel injection starting point up to the end of compression stroke where the piston is at top dead centre. The fuel injec ed droplets distribution are assumed to be known and the details of fuel drup formation are not considered. The FLUENT software has been used to study the internal mi ture formation in a cylinder of an automotive engine. In order to model the f el injection penetrafon II d mixing process which is time dependent in the combustion chamhe ,a deformable moving mesh model has been used