Optimal Ignition Timing Prediction Based on Premixed Ratio and Combustion Duration Using the Multiple Vibe 2-Zone Combustion Model

The depletion of fossil fuel supplies and the harmful environmental effects of combustion have emerged as significant issues. One viable approach to address these challenges is optimizing fuel injection timing to improve diesel engine performance. This work studies the effects of ignition timing (IT) and premixed ratio (PR) on the performance of a diesel engine at various combustion durations (CDs) and engine loads using the Multiple Vibe 2-Zone model of the AVL BOOST program. The predictive models of optimal ITs according to CD, PR, and engine load were established based on the engine′s maximum power and minimum brake-specific fuel consumption. The findings show that optimal IT and CD correlations are linear at every PR and engine load. The optimal IT rises with increasing CD and reducing PR and engine load. CD has the most significant effect on optimal IT, followed by PR, and engine load has the least influence. The largest differences in optimal IT for the maximum torque and power are 1.0, 2.3, and 11.1 crank angle degrees when changing the engine load, PR, and CD, respectively. Meanwhile, for the optimum IT to achieve minimum brake-specific fuel consumption, those corresponding values are 1.0, 2.0, and 11.0 crank angle degrees. This study aids in lowering the resources, time, and cost needed to conduct experiments to determine the ideal injection timing of the engine.