Vibration Measurement and Analysis of a Turbocharger Under Aerodynamic Excitation

In order to investigate the high vibration response of a diesel engine turbocharger caused by aerodynamic excitation，a fluid structure coupling model for the whole turbocharger was established using the unidirectional transient fluid structure coupling method，and the vibration response of key components was studied. The time-domain and frequency-domain characteristics of aerodynamic excitation of the turbine and impeller blades were thoroughly compared and discussed，and the structural vibration response characteristics under such excitation were quantitatively analyzed. The accuracy of the model was verified by the turbocharger vibration measurement. The absolute error of the accelerated vibration level under each condition does not exceed 6 dB，and the relative error does not exceed 4% compared to the measured data. The results show that in the goose system，the amplitude of the pressure fluctuation of the leaf turbine is 4 times of the turbine end，which causes the vibration amplitude of the impeller to be an average of 3 to 4 times of the turbine and the rotating shaft. The maximum vibration amplitude of 209.5 µm occurs at the gap between the leaf top. The largest housing vibration intensity of 322.2 m/s2 occurs at the inner wall of the compressor outlet close to the side of the bearing body. © 2024 Chinese Society for Internal Combustion Engines. All rights reserved.