A rate-of-injection model for predicting single and double injection with or without fusion.

Area of Science:

• Automotive Engineering
• Combustion Science
• Fluid Dynamics

Background:

• Accurate prediction of instantaneous injected fuel mass is crucial for automotive applications, including Computational Fluid Dynamics (CFD) and engine control.
• Diesel engines commonly employ multiple injection strategies, but these can be affected by injection fusion, where successive injections merge due to short intervals.

Purpose of the Study:

• To develop a novel model for predicting the instantaneous mass flow rate of diesel injectors.
• To enhance the model for predicting split injection scenarios, specifically addressing injection fusion.
• To validate the model's universality across different injector types and operating conditions.

Main Methods:

• Developed an analytical model based on the solution of a first-order linear dynamic system subjected to an impulse.
• Conducted experimental investigations on a solenoid indirect-action injector under 33 varied conditions (injection pressure, backpressure, duration).
• Validated the model against experimental data for single and split injection strategies, including cases with injection fusion.

Main Results:

• The proposed model accurately predicts instantaneous fuel mass flow rate for single injection strategies.
• The enhanced model successfully predicts split injections, both with and without injection fusion.
• The model demonstrated universality by accurately simulating a piezoelectric injector with varying fusion levels from literature.

Conclusions:

• The developed model provides a reliable method for predicting instantaneous fuel mass flow rate in diesel engines.
• The model effectively accounts for injection fusion, a critical phenomenon in modern diesel injection strategies.
• The validated approach offers a versatile tool for automotive applications requiring precise fuel injection modeling.