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A methodology has been developed by the authors, in which non-intrusive measurements (engine block vibration) are used for diagnostic purposes of combustion process in Diesel engines. A previous paper of the authors has been devoted to demonstrate the direct relationship between in-cylinder pressure and accelerometer signals, when the vibration transducer is placed in sensitive location. Moreover, in the engine block vibration a frequency band in which such a relationship is very strong has been selected. The aim of this work is to provide a deeper insight into the effects of injection parameters on engine block vibration, in order to investigate the possibility of detecting modification of the in-cylinder pressure evolution by means of the accelerometer signal with the final objective of optimizing the combustion process by means of non-intrusive transducer.

Concerns about the harmful exhaust emissions of internal combustion engines have imposed the employment of aftertreatment devices to reduce their impacts both on health and environment. System modeling of engine and aftertreatment devices is required not only to provide an accurate assessment of the engine and aftertreatment devices performances as single elements but also to quantify the complex interaction of these components from a thermo fluid perspective. The work focuses on development of a model capable of predicting temporal and spatial evolution of thermo-fluid quantities and chemical species in a diesel oxidation catalyst (DOC). The developed model allows to investigate the influence of thermal characteristics and gas composition on the evolution of the phenomena occurring in the device which deeply reflect on the particulate filter behavior during regeneration phase.

A previously developed injection system model has been enhanced including a quasi-dimensional, multi-zone, direct injection (DI) diesel combustion model, with the aim of taking into account the actual injection process, the spray formation and the droplet heating-vaporization processes. Such a goal is obtained by means of the integration of different modeling approaches. In a commercial simulation environment, a lumped parameter mechanical-hydraulic scheme is used to model the injection process, in terms of fuel flow rate and injection pressure. The spray formation processes and the droplet vaporization phenomena are then implemented in a self developed computation code, accounting for finite thermal conductibility of the liquid phase fuel.