Influence of turbulence on full flowing culvert scour

• Main Author: Sun, Qian
• Other Authors: Lim Siow Yong
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/71160
• Institution: Nanyang Technological University

Culvert is a structure to provide continuity flow through the stream crossing such that water, sediments, debris and aquatic organisms can pass through. Soil near downstream of the culvert outlet is easily washed away by flow, thus scouring at downstream of culvert outlet is a common problem that can lead to damage or complete failure of the culvert structure and adjacent land. Numerous studies have been conducted on scour hole under culvert outlet over the past years, which has led to a certain understanding on the effect of flow variables to the development of scour at culvert outlet. However, the influence of turbulence intensity has not been addressed. To extend current understanding on the impact of flow parameters, a series of experiments were carried out in the hydraulic laboratory to investigate the effect of turbulence intensity on the scour profile. This study confirmed that turbulence intensity has a significant impact on the scour hole profile. A more turbulent flow will deepen, widen and shorten the scour hole geometry, and result in a bigger volume of scour hole. The location of maximum scour depth is brought nearer to the origin, and a flatter dune is noticed with a more turbulent flow. The effect of turbulence is mainly before the location of the maximum scour depth Ldse, the characteristics of velocities such as Vx, TKE, AKE and RSS are found to have a bigger magnitude before Ldse, and these velocity characteristics are not affected after Ldse. However, TI is found to be bigger after Ldse.