Study of fuel injection in a port injection engine with indirect injection with a special look at the impact on the performance of fuel injection timing and amount of pollutants

For spark ignition engines, the fuel-air mixture preparation process and injection timing mechanism are known to have a significant influence on engine performance and exhaust emissions. Injection timing mechanism is effective on fuel mixture preparation and fuel vaporization and also HC production. In this paper,a model of a 4 cylinder multi-point fuel injection engine was prepared using a fluid dynamic code. By this code one-dimensional, unsteady, multiphase flow in the intake port has been modeled to study the mixture formation process in the intake port for 2600 and 6000 rpm in part load and full load condition. Accuracy of model was verified using experimental results of engine testing and it shows good agreement between the model and the real engine According to the present investigation, a key point was found to design optimum injection timing for different engine velocities and loads