Observations of flow distributions on wide wing-wall abutment in two-stage channel

• Main Author: Kenny
• Other Authors: Lim Siow Yong
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Civil engineering::Water resources
• Online Access: http://hdl.handle.net/10356/74739
• Institution: Nanyang Technological University

Scouring around abutment is a detrimental process to the structure foundation in which it causes the sediment bed to be undermined, making the foundation being shallower than it was designed and eventually leading to structural failure. Hence, emphasizing on the importance of being able to predict the flow in scouring process around the structure. The objective of this study is to investigate the flow field around a wide 45◦ wing-wall abutment in the equilibrium scour hole condition under clear water condition. The flow field measurements were done by using an Acoustic Doppler Velocimeter (ADV). The experiment was conducted with a 80 cm wide wing-wall abutment situated in the floodplain sand bed of a 19 m long and 1.6 m wide two-stage channel flume. In the equilibrium state, it was observed that there were 2 scour holes and 1 deposition ridge formed around the abutment. Equilibrium state of the sediment bed was frozen to reduce disturbance on the geometry during flow measurements. The results of the flow field in terms of the velocity vectors and contours of turbulent intensities, turbulent kinetic energy and the Reynold shear stress in the scour hole are presented. The Reynold shear stress, turbulent intensities and turbulent kinetic energy share similar contour trend. In the sections where scour hole is shallow, the 3 components contours show an increase in value closer to the abutment. On the other hand, at section where scour hole is the deepest, high value of the 3 components are observed on the region between ridge at the end of scour hole.