The Accuracy of the Mean Value Engine Model Affected Little by the Accuracy of Compressor Mass Flow Rate Model for a Marine Diesel Engine

The digital twin concept proves to be highly advantageous for smart ships as it allows the digital model to adapt in real time with changes in the physical ship. The mean value engine model (MVEM) is investigated with three different compressor mass flow rate models: a 2D interpolation model (2D), an experience-based M-JENSEN (MJ) model, and a physics-based Kang Song (KS) model. Each model is studied on a MAN 7S80ME engine with ABB A270 turbochargers. The root-mean-square errors (RMSE) for the test data are approximately 2.5 m^3/s for the 2D model, 2.8 m^3/s for the KS model, and 0.56 m^3/s for the MJ model. For the training data, the RMSEs are around 0.0, 3.0, and 0.69 m^3/s , respectively. When coupling each model to the MVEM, it is observed that the calculated values differ only in the turbocharger speed. The RMREs under steady-state processes are 0.54