Combustion Characteristics of a Single-Cylinder Open-Chamber Diesel Engine

Abstract

The combustion characteristics of an open-chamber diesel engine were examined by means of heat-release analysis and flame luminosity measurements. Increasing the load was found to decrease premixed burning and correspondingly to increase diffusion burning. During most of the diffusion combustion the burning rate of the fuel appeared to be directly proportional to the amount of unburned fuel present in the cylinder. The duration of heat release in crank-angle degrees increased linearly with load and, in general, increased with decreasing engine speed and retarded injection timing. The measured duration of flame luminosity was significantly longer than the calculated duration of heat release, which suggested that emission of radiation continued long after the heat-release reactions ceased.