Fig. 7 shows the results for the compressor model and the heat transfer model ˙Qc. The measurements represented by
hc,adim˙ c are relieved from the heat transfer. Measurements 1-74 represent the cold measurement, data points
75-176 are measured with injection. Even in the zoomed section with low turbocharger power the model fits the
data well. The averaged root mean squared error of a seven fold cross validation is 39.6W. At operation points with
low compressor load the modelled heat transfer into the compressor housing has a large effect with respect to the
aerodynamic power. Especially for the data points 1 to 15 the contribution of enthalpy by the heat transfer is large.
The heat transfer into the compressor housing ranges from 100W to 300W.
Fig. 9 shows the results for the turbine power model Pt and the heat transfer model ˙Qt. The turbine power is compared
to the sum of friction losses Pf and the compressor power Pc. Here the model quality for the aerodynamic turbine power is slightly worse that the aerodynamic compressor power model. Depending on the engine operation point the modelled heat transfer varies from 100W to 2000W.