Comparison of a turbocharger model based on isentropic efficiency maps with a parametric approach based on Euler's turbo-machinery equation

Faults in the intake and exhaust path of turbocharged common rail Diesel engines can lead to an increase of emissions and performance losses. Application of turbocharger models can help to detect and diagnose more faults as standard fault detection methods. The modeling of the turbocharger for onboard fault diagnosis can be obtained by different models. The differences between an approach based on the isentropic efficiencies and an approach based on Euler's turbo-machinery equation are investigated in this paper. The two models for a GT1749MV turbocharger are parameterized with data from the engine testbed. The comparison is applied by issues of measured model inputs, number of intern parameters, parameterization effort and model accuracy. Both models are compared regarding the application for onboard diagnosis.