Convegni ATI - Accesso riservato soci CTI

Autore: A. E. Catania, S. d’ Ambrosio, A. Ferrari, D. Misul, A. Mittica, E. Spessa

Collana: CA - 66 - Rende 2011

Note:
A detailed mathematical model for Solenoid Common Rail and Electronic Unit Injectors was developed to support experimentation, design and performance optimization. The thermo-fluid dynamics of the hydraulic circuit components, including pumping chamber, internal injector pipes and nozzle was modeled in conjunction with the driving-circuit
electromagnetics and the mechanics of needle, rocker arm and follower as well as lever subsystems. An effective model of the electromagnetic driving circuit was used to predict the temporal distribution of the force acting on the pilot-valve armature.
The model was based on the experimental time-histories of the current and voltage signals to the solenoid.
One-dimensional flow equations in conservation form were used in the fuel injection system models to simulate wave propagation phenomena throughout the rail to injector ducts and along the injector high-pressure drilled pipes. In order to simulate the temperature variations due to the fuel compressibility, the energy equation was used in addition to mass conservation and momentum balance equations. Furthermore, an advanced friction model, which accounted for the frequency dependent friction by an original approach, was also included in the momentum balance equation.
The models were applied to better understand the cause and effect relationships in the analysis of the system transients
during CR or EUI operation at engine-like working conditions.