A Numerical Study of Fuel Evaporation and Transportation in the Intake Manifold of a Port-Injected Spark-Ignition Engine

Abstract

The paper presents a computer simulation of mixture preparation in the inlet port of a port-injected spark-ignition engine operating at low load and low speed. The solution of the models at successive crank angles allows mixture preparation in the port to be investigated under steady engine operation. The main features of the simulation are: monosize spray of a single-component fuel, evaporation of the spray droplets during flight, evaporation of the fuel film, fuel film flow along the manifold walls and unsteady air flow during the induction period. Use of the simulation allowed investigation of the effects of: manifold wall and air temperatures, spray-droplet size, injection timing, injector aim, fuel voltatility and the use of methanol as the fuel.