Study on predicting combustion and NOx formation in diesel engines from scale model experiments

The paper discusses the methodology of predicting combustion and NO formati on in large diesel engines from scale model experiments, together with the experimental results compared with the theoretical predictions. Combustion similarity means that flow patterns and flame distribution develop similarl y in differently sized engines, so allowing heat release rates and thermal efficiency to be predicted from scale model experiments. One of the objecti ves of this research is to validate the establishment of the combustion sim ilarity by experiments. Additionally, an algorithm to predict NO emissions is also established in this paper, based on the combustion similarity and u nique characteristics of NO formation. An experimental data was obtained wi th two sets of similar engines ranging from 85 to 125 and from 600 to 800 m m bore. The results showed good agreement with the theoretical predictions, indicating possibility of the scale model experiment for diesel engine com bustion.