Investigation and Comparison of the Prediction Capabilities of Multiple 0D/1D Combustion Calibration Strategies Using different Turbocharger Systems as Calibration Basis 2022-01-0378

Reliably calibrated simulation and combustion models not only enable the prediction of non-validated operating points, but also compensate for the time that would be required for costly test bench measurements. Under the premise of investigating various turbocharging concepts for a combustion engine without the need for recalibration, the present work will discuss the influence of two different exhaust gas turbocharger systems on model calibration. Replacing turbochargers is a practical way to test the predictive performance of simulations, since they can drastically affect and change the thermodynamic boundary conditions for comparable operating points. On the one hand, the choice of the appropriate calibration strategy and, on the other hand, the interchangeability of the respective calibration will be discussed. The interchangeability is intended to prove that, despite significant thermodynamic differences in the use of two turbochargers, the calibration of one engine model is sufficient to predict engine behavior and emissions of both concepts. Baseline for the calibrations are two independent test bench measurements on a 1950 cc four cylinder diesel engine, which conceptually differ in the application of a wastegate and a VGT turbocharger. The simulations are based on a predictive modeling approach within the GT Suite software. The results show that all studied combustion parameters could be predicted within about 1-10 % deviation regardless of the calibration strategy. However, minor differences emerge when considering the prediction of pressure curves and burn rates. The main question regarding combustion model transfer can be evaluated as a positive success, especially for the prediction of combustion. Higher but partially acceptable deviations occurred regarding the emission model transfer.