An advanced real-time capable mixture controlled combustion model

• ROHR prediction considering the premixed and two diffusion combustion contributions.
• Unburned fuel available for combustion determined based on first principles.
• Fuel for premixed combustion determined based on the duration of ignition delay period.
• Mechanistically based combustion rate reduction on the oxygen availability.
• Modeling framework is capable of considering arbitrary number of sprays.

The paper presents an innovative and advanced MCC (mixture controlled combustion). The MCC model is coupled to the innovative mechanistically based 0D spray model presented in a companion paper [1] that provides inputs on fuel mass distribution. Advanced MCC model is embedded into a 2-zone combustion modeling framework. Advanced MCC predicts ROHR (Rate-Of-Heat-Release) as the combination of the premixed and two diffusion parts, which correspond to rich and lean spray region. It also calculates the amount of fuel available for premixed combustion based on the duration of the ignition delay period. In addition, it reduces the reaction rate based on the oxygen availability using mechanistic basis, based on evaporation rate and based on mechanistically determined fuel amount that has reached the walls. High level of model predictability was confirmed by good agreement between the simulated and the measured ROHR traces over very broad operating range of the engine by using fixed parameters of the advanced MCC model and the spray model. Moreover, the applied modeling framework with embedded innovative spray and advanced MCC model features HiL (Hardware-in-the-Loop) compatible computational times.