Theoretical and Experimental Study of Multi-Phase Flow in the Intake Port of a Port Fuel Injection Engine

For spark ignition engines, the fuel-air mixture preparation process is known to have a significant influence on engine performance and exhaust emissions. In this paper, a one-dimensional, unsteady, multiphase flow has been modeled to study the mixture formation process in the intake manifold for a port-injected gasoline engine. In addition, an experimental study is made to characterize the spray characteristics of a Multi-hole injector used in the engine. One-dimensional airflow and wall fuel film flow and a two dimensional fuel droplet flow have been modeled and it includes the effects of in-cylinder mixture back flows into the port. As a result, predictions are obtained that provide detailed picture of the air-fuel mixture properties along the intake port. In addition, comparison was made on injection characteristics of the multi-hole injectors and its effects on multi-phase flow property on various fuel pressures and temperatures.