Visualization of the Evaporating Process of Fuel Spray in the Cylinder of a Diesel Engine

Abstract

A single cylinder engine with the combustion chamber mounted on the piston was designed to allow visualization in the direction of the cylinder axis. By using this engine, the evaporating process of the fuel injected into the combustion chamber was observed. High-speed Schlieren, shadowgraph, and back-illuminated photographs were taken for detailed observation of the combustion chambers with a single hole injector and a swirl injector which have different atomization characteristics. The chamber with a single hole injector showed strong collision of the spray with the bottom of the chamber and fast evaporation. That with a swirl injector showed no evidence of such collision and relatively slow evaporation.