# Vibration and Aerodynamic Analysis and Optimization Design of a Test Centrifuge

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Numerical Model of Test Centrifuge

## 3. Vibration Numerical Simulation and Structural Improvement Design of the Test Centrifuge

#### 3.1. Vibration of the Test Centrifuge

_{bpfi}of the rolling element passing through the inner ring, the rotation frequency f

_{bsf}of the rolling element, and selecting the maximum value as the harmonic response analysis frequency to simulate the bearing excitation. According to Equations (4)–(6), the frequency of the rolling part passing through the inner ring and the rotation frequency of the rolling part were calculated.

_{i}is the bearing inner ring raceway diameter, D

_{o}is the bearing outer ring raceway diameter, d is the rolling element diameter, α is the rolling element contact angle, Z is the number of rollers, and f

_{i}is the rotation frequency of the inner ring around the center of the circle. The radial bearing parameters and thrust bearing parameters are shown in Table 1. The frequency of the rolling element of the radial bearing through the inner ring was calculated to be 11.57 Hz by Equation (5), and the frequency of the rolling element of the radial bearing through the inner ring was calculated to be 12.74 Hz. The rolling element rotation frequency of the radial bearing was calculated to be 4.16 Hz by Equation (6), and the rolling element rotation frequency of the radial bearing was calculated to be 5.33 Hz.

#### 3.2. Harmonic Response Analysis Results

_{1}and thrust bearing stiffness K

_{2}were calculated according to Equation (7) [29].

_{3}is the diameter of the roller, and R is the radial load.

#### 3.3. Improvement Design of Mounting Seat

## 4. Aerodynamic Numerical Simulation and Structural Optimization Design of Test Centrifuge

#### 4.1. Aerodynamic Numerical Simulation Method

^{3}at 25 °C, C is the drag coefficient, S is the windward area, and v is the flow velocity of the medium. According to Equation (8), the drag coefficient (lift coefficient) calculation Equation (9) is obtained.

#### 4.2. The Influence of the Whole-Package Shell of the Test Centrifuge on the Aerodynamic Resistance

#### 4.3. The Influence of Fairing on the Aerodynamic Performance of Centrifuge

#### 4.4. Optimization Design of Fairing

## 5. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

## References

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**Figure 4.**Vibration analysis results: (

**a**) Unbalanced excitation load; (

**b**) External vibration load; (

**c**) Vibration load of bearing.

**Figure 5.**Vibration analysis results: (

**a**) Vibration velocity response of the mounting seat under unbalanced excitation; (

**b**) Vibration velocity response of mounting base under external vibration excitation; (

**c**) Vibration velocity response of mounting seat under bearing vibration excitation.

**Figure 6.**Vibration response spectrum: (

**a**) Unbalanced excitation; (

**b**) External vibration excitation; (

**c**) Bearing vibration excitation.

**Figure 8.**The improved vibration analysis results: (

**a**) Vibration velocity response of the mounting seat under unbalanced excitation; (

**b**) Vibration velocity response of mounting base under external vibration excitation; (

**c**) Vibration velocity response of mounting seat under bearing vibration excitation.

**Figure 9.**The improved vibration analysis results: (

**a**) Vibration response spectrum of the mounting seat under unbalanced excitation; (

**b**) Vibration response spectrum of the mounting base under external vibration excitation; (

**c**) Vibration response spectrum of the mounting seat under bearing vibration excitation.

**Figure 12.**Illustration of model: (

**a**) Test centrifuge; (

**b**) Test centrifuge with whole package shell; (

**c**) Test centrifuge with a fairing.

**Figure 13.**Vortex core diagram: (

**a**) Schematic diagram of the vortex core area; (

**b**) Schematic diagram of the vortex core area after adding the whole-package shell.

**Figure 14.**Velocity vector diagram: (

**a**) Test centrifuge with whole package shell; (

**b**) Test centrifuge with fairing.

Parameter | Radial Bearing | Thrust Bearing |
---|---|---|

D/mm | 685 | 800 |

D_{i}/mm | 770 | 1060 |

D_{o}/mm | 727.5 | 930 |

d/mm | 55 | 55 |

α/° | 0 | 40 |

Z | 34 | 38 |

f_{i}/Hz | 0.633 | 0.633 |

Incentive Type | Mounting Seat Vibration (mm/s) |
---|---|

Unbalanced excitation | 2.4998 |

External vibration excitation | 0.0230 |

Bearing vibration | 5.2242 |

Total | 7.747 |

Incentive Type | Mounting Seat Vibration (mm/s) |
---|---|

Unbalanced excitation | 0.019 |

External vibration excitation | 0.915 |

Bearing vibration | 0.820 |

Total | 1.754 |

Incentive Type | Mounting Seat Vibration |
---|---|

Test centrifuge running space diameter/m | 22 |

Test centrifuge running space height/m | 5 |

air density/(kg/m^{3}) | 1.205 |

temperature/°C | 20 |

Test centrifuge rotating speed/rpm | 38 |

Type | Grids Number (Million) | Drag Coefficient |
---|---|---|

Grid 1 | 0.82 | 0.4916 |

Grid 2 | 1.24 | 0.4823 |

Grid 3 | 1.67 | 0.4797 |

Flow Analysis Model | Average Flow Velocity (m/s) |
---|---|

Whole-package shell + fairing | 16.67 |

Whole-package shell | 17.02 |

Flow Analysis Model | Drag (N) | Lift (N) |
---|---|---|

Whole-package shell + fairing | 1469.67 | 96.61 |

Whole-package shell | 1885.19 | 204.30 |

Flow Analysis Model | X-Direction | Z-Direction |
---|---|---|

Whole-package shell + fairing | 23.83 | 66.84 |

Whole-package shell | 23.60 | 47.79 |

Flow Analysis Model | Drag Coefficient | Lift Coefficient |
---|---|---|

Whole-package shell + fairing | 0.3796 | 0.0089 |

Whole-package shell | 0.4717 | 0.0252 |

Extension Width (mm) | Drag Coefficient |
---|---|

250 | 0.3941 |

350 | 0.3919 |

500 | 0.3873 |

700 | 0.38 |

950 | 0.349 |

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**MDPI and ACS Style**

Deng, C.; He, L.; Tan, Z.; Jia, X.
Vibration and Aerodynamic Analysis and Optimization Design of a Test Centrifuge. *Vibration* **2023**, *6*, 917-931.
https://doi.org/10.3390/vibration6040054

**AMA Style**

Deng C, He L, Tan Z, Jia X.
Vibration and Aerodynamic Analysis and Optimization Design of a Test Centrifuge. *Vibration*. 2023; 6(4):917-931.
https://doi.org/10.3390/vibration6040054

**Chicago/Turabian Style**

Deng, Chunyan, Lidong He, Zhifu Tan, and Xingyun Jia.
2023. "Vibration and Aerodynamic Analysis and Optimization Design of a Test Centrifuge" *Vibration* 6, no. 4: 917-931.
https://doi.org/10.3390/vibration6040054