Modeling of combustion phasing of a reactivity-controlled compression ignition engine for control applications
© IMechE 2015. Reactivity-controlled compression ignition (RCCI) is a promising combustion strategy to achieve near-zero NOx and soot emissions and diesel-like efficiencies. Model-based control of RCCI combustion phasing requires a computationally efficient combustion model that encompasses factors such as injection timings, fuel blend composition, and reactivity. In this work, physics-based models are developed to predict the onset of auto-ignition in RCCI and to estimate the burn duration based on an approximation of the spontaneous ignition front speed. A mean value control-oriented model of RCCI is then developed by combining the auto-ignition model, the burn duration model, and a Wiebe function to predict combustion phasing. The control-oriented model is parameterized and validated using simulation data from an experimentally validated, detailed computational fluid dynamics combustion model developed using the KIVA-3V code. The validation results show that the control-oriented model can predict the start of combustion, burn duration, and crank angle of 50% burnt fuel with an average error of less than 2 crank angle degrees. Thus, the control-oriented model demonstrates sufficient accuracy in predicting RCCI combustion phasing for control applications. The control-oriented model is an integral part of designing a model-based controller, which in the case of RCCI is of paramount importance due to various attributes concerning combustion, particularly for transient engine operation.
International Journal of Engine Research
Khodadadi Sadabadi, K.,
Modeling of combustion phasing of a reactivity-controlled compression ignition engine for control applications.
International Journal of Engine Research,
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