# Experimental and Numerical Analysis of Deformation in a Rotating RC Helicopter Blade

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## Abstract

**:**

## 1. Introduction

## 2. Experimental Approach

## 3. Numerical Model

#### 3.1. Shape Acquisition

#### 3.2. Material Properties

^{−3}.

#### 3.3. Model

^{−3}and a viscosity of 1.7894 × 10

^{−5}kg m

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^{−1}.

## 4. Results and Discussion

- The initial models used an inaccurate 3D shape obtained from a single image acquisition from the DAVID structured light scanner, without the use of dry powder;
- The Young’s modulus was obtained using a method that was dependent on the inaccurate 3D shape, which in turn resulted in a wrong result;
- The existence of unmodelled gaps between the blades and the hub, which allowed for free rotation of the blades;
- Instability of the rotation axis, as it deformed due to its extended use.

## 5. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## Abbreviations

ABS | Acrylonitrile butadiene styrene |

CFD | Computational Fluid Dynamics |

DIC | Digital Image Correlation |

FEA | Finite Element Analysis |

fps | Frames per second |

LED | Light Emitting Diode |

MP | Megapixel |

RC | Remote Controlled |

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**Figure 10.**The effects of reflection in the structured light shape acquisition procedure. (

**a**) Without dry powder reflections cause geometry errors. (

**b**) With dry powder the obtained surface correctly matches the geometry.

**Figure 15.**Loading results from the Instrom test machine, resulting in an approximation of the blade’s Young’s modulus.

**Figure 18.**Comparison of the blades’ rotating position before (purple) and after (green) reducing gaps.

**Figure 19.**Stabilization of the RC helicopter’s axis, using a bearing and a support built out of teflon.

**Figure 25.**(

**a**) Comparison of the experimental and numeric results for the displacements along a blade chord; (

**b**) Percentage difference between the two methods.

Parameter | Value |
---|---|

${C}_{{\epsilon}_{1}}$ | 1.44 |

${C}_{{\epsilon}_{2}}$ | 1.92 |

${C}_{1}$ | 1.8 |

${C}_{2}$ | 0.6 |

${C}_{1}^{\prime}$ | 0.5 |

${C}_{2}^{\prime}$ | 0.3 |

${C}_{\mu}$ | 0.09 |

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## Share and Cite

**MDPI and ACS Style**

Sousa, P.J.; Barros, F.; Tavares, P.J.; Moreira, P.M.G.P.
Experimental and Numerical Analysis of Deformation in a Rotating RC Helicopter Blade. *Int. J. Turbomach. Propuls. Power* **2020**, *5*, 13.
https://doi.org/10.3390/ijtpp5030013

**AMA Style**

Sousa PJ, Barros F, Tavares PJ, Moreira PMGP.
Experimental and Numerical Analysis of Deformation in a Rotating RC Helicopter Blade. *International Journal of Turbomachinery, Propulsion and Power*. 2020; 5(3):13.
https://doi.org/10.3390/ijtpp5030013

**Chicago/Turabian Style**

Sousa, Pedro J., Francisco Barros, Paulo J. Tavares, and Pedro M. G. P. Moreira.
2020. "Experimental and Numerical Analysis of Deformation in a Rotating RC Helicopter Blade" *International Journal of Turbomachinery, Propulsion and Power* 5, no. 3: 13.
https://doi.org/10.3390/ijtpp5030013