# Advanced Engine Technologies for Turbochargers Solutions
## 3 Materials and Methods
### Stand Testing of Generator Hybrid Turbocompressor Equipment  
To validate the functional characteristics of the new concept, subsystems were designed such as the coupling shaft between the turbocharger and the electricity generator, the reducer, and the generated electricity measurement system. The physical model was experimentally subjected to a stand for testing the CIMAT turbocharger (Figure 5). This allows for the evaluation of the functional characteristics of the compressed air-driven turbocharger at pressures of 0.1... 0.2 MPa, which replaces the flue gas flow discharged from the cylinders of the internal combustion engine [45].  
The research undertaken under the stabilized regime allowed the evaluation of the following functional parameters of the system (Table 1):  
* Compressed air pressure intended to drive the turbine;
* Speed of the turbocharger shaft of the electricity generator;
* Voltage and current values (excitation and load) of the generated electric current.  
The experimental investigations, undertaken on the stand dedicated to the diagnosis of turbochargers, allowed us to obtain technical data which ensured the evaluation of the following dependencies:  
1. The speed variation of the turbocharger rotor over time (Figure 6). The start-up time of the turbine is 3.2 s, and the maximum rotational velocity of the shaft is 160,000 rpm;  
Figure 5: The hybrid turbocharger connected to compressed air of the CIMAT Turbo Test Pro.  
Figure 6: Turbocharger shaft speed variation (experimental result).  
2. The variation, over time, of the current voltage and the power developed by the electric generator (Figure 7); the voltage resulting from the experimental work in relation to the time has the value from 0 to 23 Volts; the current intensity resulting from the experiments range between 0 and 4.5 Amperes; and the electrical power ranges from 0 to 102 Watts.  
Analog measuring devices and appropriate calculation programs were used to determine the electrical measurements of the generator (Figure 8).  
Table 2 indicates the resulting parameters, namely the evaluated parameter, the unit of measurement, and the value of the parameter.  
Figure 8: Diagram of the exhaust system [46].  
Figure 7: Time dependence of current, voltage current, and power generated by the hybrid turbo-charger (experimental result).  
The conclusions formed from the tests are the following:  
* The concept of hybrid turbocharger works feasibly;
* The turbocharger shaft speed is positioned in the interval from 140,000-160,000 rpm and due to the mechanical reducer/gear ratio 1:10, the electric generator shaft speed is 14,000-16,000 rpm;
* The electric generator (XD-3420) can be driven by the turbined it generates energies of 0.67-0.68 Wh in approximate 21 s of the proved experimental phase, depending on the values of pressure and compressed air flow in the turbine blades;
* An electromagnetic coupling controlled by an electronic processor must be inserted between the turbocharger and the speed reducer;  
In order to study in the virtual environment and the variation of the functional parameters of the designed system, a model was designed that was tested with AMESim software [45; 47].