A Time-Dependent Spatial Model for Radiant Heat Transfer in Diesel Engines

We have developed a fully three-dimensional spatial model of the instantaneous radiation heat transfer in direct ignition diesel engines. The model is based on the assumption that the primary source of radiation is from the soot formed on the fuel-rich side of the combusting spray plumes. The model then calculates view-factors to the various regions from the evolving plume using a spray correlation model. The soot is assumed to be a grey body radiating through an optically thin medium to the relatively cool components of the combustion chamber. Preliminary calculations using the model indicate that there are significant spatial and temporal variations in the incident radiation on various regions in the combustion chamber. These calculations were performed for a geometry and operating conditions of a production turbocharged medium speed engine at full load conditions.