Diesel Spray Combustion - An Optical Imaging Analysis 930862
Formation, ignition and combustion of diesel fuel sprays have been observed in the combustion chamber of an optically accessed single cylinder diesel engine. Two different combustion chamber geometries allowed the fuel sprays to be studied under quiescent and cross flow conditions.
The study of the spatial distribution with different single shot photography techniques is complemented with an investigation of the temporal development of spray and flame propagation by an electronic high-speed line-scan technique. This continuous, time resolved analysis technique allows to resolve the influence of temporal variations imposed on the spray propagation and combustion by the fuel injection schedule.
The application of these methods to the investigation of diesel sprays highlights mechanisms which govern the propagation and distribution of fuel sprays, fuel evaporation and the formation of a combustible fuel-air mixture. The characteristics of ignition and flame propagation are seen to result mainly from mixture formation and the ongoing delivery of combustible mixture throughout the injection period.