Combustion characteristics of residual fuel sprays in diesel engines

To improve the burning conditions of the residual fuel in the combustion chamber of a diesel engine, visualization and combustion diagnoses of the residual fuel spray were carried out. First, physical effects of the impingement of spray on the combustion chamber wall and the air swirl were verified. Next, the effect of increase of air temperature in the combustion chamber on the ignition delay and combustion conditions were examined. As a result, it was made clear that some means of improving the evaporation rate is necessary for the residual spray. But it is difficult to improve the evaporation rate of the residual components themselves. So, as an alternative means, the acceleration of the combustion of the distillate components included in the residual fuel must be achieved to promote the combustion of the residual components.