# Acoustic Identification of Turbocharger Impeller Mistuning—A New Tool for Low Emission Engine Development

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## Abstract

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## Featured Application

**The acoustic method for identification of bladed disc mistuning described in this work will be useful for accelerating the development of new turbochargers and other impeller machines while significantly reducing costs.**

## Abstract

## 1. Introduction

## 2. Computational Modelling of Tuned Bladed Wheels

**M**—mass matrix,

**G**—gyroscopic matrix,

**K**—structural damping matrix and

**C**—stiffness matrix. Vector

**y**represents displacements and rotations at nodes and

**f**the external forces. The stiffness matrix contains centrifugal stiffness and softening effects resulting from the static analysis under centrifugal, thermal and gas loads. In a non-rotating state, the bladed rotor system eigenvalues and eigenmodes can be found by solving the generalized eigenvalue problem.

## 3. Arrangement of the Laboratory Experiment

## 4. Results of the Acoustic method for Mistuning Identification

#### 4.1. Computational Finite Element Model of the Turbine Impeller

#### 4.2. Measurement Results

_{i}of the individual blades differ. The mistuning of the neighbouring blades is reflected in the relative eigenfrequency deviations

## 5. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 10.**Fast Fourier transform (FFT) analysis of measured response signal using the laser vibrometer and eigenfrequencies from the FE model—measured without additional weights.

**Figure 11.**FFT analysis of measured response signal using the laser vibrometer and eigenfrequencies from the FE model—measured with additional weights.

**Figure 12.**FFT analysis of measured response signal using the measuring microphone and eigenfrequencies from the FE model—measured with additional weights.

Mode (–) | Frequency (Hz) |
---|---|

1 | 4718 |

2 | 7737 |

3 | 9110 |

4 | 11,333 |

5 | 14,107 |

6 | 14,990 |

7 | 18,511 |

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**MDPI and ACS Style**

Píštěk, V.; Kučera, P.; Fomin, O.; Lovska, A.; Prokop, A.
Acoustic Identification of Turbocharger Impeller Mistuning—A New Tool for Low Emission Engine Development. *Appl. Sci.* **2020**, *10*, 6394.
https://doi.org/10.3390/app10186394

**AMA Style**

Píštěk V, Kučera P, Fomin O, Lovska A, Prokop A.
Acoustic Identification of Turbocharger Impeller Mistuning—A New Tool for Low Emission Engine Development. *Applied Sciences*. 2020; 10(18):6394.
https://doi.org/10.3390/app10186394

**Chicago/Turabian Style**

Píštěk, Václav, Pavel Kučera, Oleksij Fomin, Alyona Lovska, and Aleš Prokop.
2020. "Acoustic Identification of Turbocharger Impeller Mistuning—A New Tool for Low Emission Engine Development" *Applied Sciences* 10, no. 18: 6394.
https://doi.org/10.3390/app10186394