# Scour Development Around an Oblong Bridge Pier: A Numerical and Experimental Study

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## Abstract

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## 1. Introduction

## 2. The Hydrodynamic Model

#### 2.1. Framework

#### 2.2. Flow Computation

#### 2.3. Sediment Transport Equations

## 3. Local Scouring Experimental Data

## 4. Numerical Model Setup

#### 4.1. Mesh Geometrical Dimensions

#### 4.2. Boundary Conditions and Input Parameters

## 5. Results and Discussion

#### 5.1. General Considerations

#### 5.2. Scour Depth Estimates

#### 5.3. Bed Morphology

#### 5.4. Bed Shear Stress

## 6. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Conflicts of Interest

## References

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**Figure 4.**Scour hole and deposition region around the oblong bridge pier (dimensions in meters). (

**a**) t = 15 min. (

**b**) t = 60 min. (

**c**) t = 240 min. (

**d**) t = 360 min. (

**e**) t = 420 min. (

**f**) t = 480 min.

**Figure 5.**Scoured bed hole profiles on the longitudinal mid-plane (

**a**) and on the plane normal to the flow direction (

**b**). Flow direction: x-axis.(

**a**) At the pier’s longitudinal mid-plane. (

**b**) At the plane normal to flow direction.

**Figure 6.**Normalized bed shear stress ($\tau /{\tau}_{m}$) contours around the oblong bridge pier. (

**a**) t = 15 min. (

**b**) t = 60 min. (

**c**) t = 240 min. (

**d**) t = 360 min. (

**e**) t = 420 min. (

**f**) t = 480 min.

Q $\left({\mathbf{m}}^{3}{\mathbf{s}}^{-1}\right)$ | h $\left(\mathbf{m}\right)$ | V $\left({\mathbf{ms}}^{-1}\right)$ | $\mathit{If}$ $(-)$ | $\mathit{Fr}$ $(-)$ | $\mathit{Re}$ $(-)$ | ${\mathit{Re}}_{\mathit{D}}$ $(-)$ | |
---|---|---|---|---|---|---|---|

Experiment | 0.0923 | 0.1440 | 0.3205 | 1.0295 | 0.2696 | 46,150 | 35,253.47 |

t (min) | ${\mathit{d}}_{\mathit{s},\mathit{measured}}$ (m) | ${\mathit{d}}_{\mathit{s},\mathit{computed}}$ (m) | ${\mathit{e}}_{\mathit{i}}$ (%) |
---|---|---|---|

15 | 0.048 | 0.036 | 25.4 |

30 | 0.061 | 0.054 | 11.8 |

60 | 0.074 | 0.072 | 2.2 |

240 | 0.111 | 0.109 | 1.7 |

300 | 0.114 | 0.114 | −0.2 |

360 | 0.117 | 0.119 | −2.3 |

390 | 0.115 | 0.121 | −5.2 |

420 | 0.120 | 0.123 | −2.4 |

450 | 0.122 | 0.125 | −2.0 |

480 | 0.125 | 0.126 | −0.5 |

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**MDPI and ACS Style**

Bento, A.M.; Pêgo, J.P.; Viseu, T.; Couto, L.
Scour Development Around an Oblong Bridge Pier: A Numerical and Experimental Study. *Water* **2023**, *15*, 2867.
https://doi.org/10.3390/w15162867

**AMA Style**

Bento AM, Pêgo JP, Viseu T, Couto L.
Scour Development Around an Oblong Bridge Pier: A Numerical and Experimental Study. *Water*. 2023; 15(16):2867.
https://doi.org/10.3390/w15162867

**Chicago/Turabian Style**

Bento, Ana Margarida, João Pedro Pêgo, Teresa Viseu, and Lúcia Couto.
2023. "Scour Development Around an Oblong Bridge Pier: A Numerical and Experimental Study" *Water* 15, no. 16: 2867.
https://doi.org/10.3390/w15162867