Jeihouni, Y., Pischinger, S., Ruhkamp, L., and Koerfer, T., "Relationship between Fuel Properties and Sensitivity Analysis of Non-Aromatic and Aromatic Fuels Used in a Single Cylinder Heavy Duty Diesel Engine," SAE Technical Paper 2011-01-0333, 2011, doi:10.4271/2011-01-0333.
Fuel properties are always considered as one of the main factors to diesel engines concerning performance and emission discussions. There are still challenges for researchers to identify the most correlating and non-correlating fuel properties and their effects on engine behavior. Statistical analyses have been applied in this study to derive the most un-correlating properties. In parallel, sensitivity analysis was performed for the fuel properties as well as to the emission and performance of the engine. On one hand, two different analyses were implemented; one with consideration of both, non-aromatic and aromatic fuels, and the other were performed separately for each individual fuel group. The results offer a different influence on each type of analysis. Finally, by considering both methods, most common correlating and non-correlating properties have been derived. In case of combustion phenomena some heterogeneous combustion were measured as base study and investigations were continued with a partly homogeneous combustion to see the effect of fuel homogenization and influence of each non-correlating properties. Separate DoE (Design of Experiment) tests have been implemented for each fuel and DoE models were developed and analyzed. Constraint points from the models and measurements have been studied in more detail and sensitivity analysis has been conducted concerning engine emissions versus fuel properties. Results display a correlation matrix of fuel properties based on Pearson method as well as sensitivities of each fuel properties to each engine emission and performance in partly homogeneous combustion. Finally, sensitivity analyses present criterions to find out the impact of each fuel and properties at each operating point and to verify the relationship between properties and engine outputs. Furthermore, it is resulted that at homogeneous combustion the highest influence of fuel properties exist in the part load and low speed area of the engine map. For the sensitivity analysis, the most independent fuel properties were applied. Results show good approaches for the NOx and PM emissions by using partly homogeneous combustion at the part load points. Besides, this analysis highlights the influence of the most independent properties to the NOx and PM emissions in different area of the engine map.