International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The main subject of this paper is the development of a multicylinder engine model for the prediction of knocking combustion and emissions such as nitrogen oxide and unburned hydrocarbons based on one-dimensional simulation. The one-dimensional simulation is widely used for combustion system layout and determination of operating parameters to achieve performance targets and comply with emission limits. The paper focuses especially on the prediction of the unburned fuel mass from the combustion process and from the scavenging during the valve overlap. The calibration of the sub-models is based on measurements on a single cylinder research engine with a displacement of approximately 6 litres. The simulation results are validated with experimental measurement results on the same research engine. The paper concludes with statements about the predictive capability of the model.

The main subject of this paper is the development of a multicylinder engine model for the prediction and optimization of engine performance based on one-dimensional (1D) simulation. 1D simulation is widely used to preoptimize engine geometry and operating parameters to achieve performance targets and comply with operational and emission constraints. Due to the short calculation times, 1D simulation allows the evaluation of a larger number of variants. As new engine concepts are developed, many operating parameters are first defined and optimized with a 1D multicylinder engine model. This model illustrates the full complexity of the engine with its geometry, turbocharging and combustion parameters. In this paper the design of experiments (DoE) method is used in connection with 1D simulation to determine the optimal engine configuration as well as parameters related to the combustion process, i.e., valve timing, compression ratio, ignition timing, excess air ratio. This approach enables the determination of the maximum engine efficiency while taking the boundary conditions and the constraints of nitrogen oxide emissions (NOx) and knock into account. The method also enables the reduction of the cylinder-to-cylinder deviations by improving the gas dynamics and the fuel metering in the main combustion chamber and in the prechamber, which is especially important for the multicylinder engine. The simulation results are validated with experimental investigations on a single cylinder research engine.