Velocity and Turbulent flow field at around the cylindrical Pier

R Karthik ,Umesh Kumar ,Abdul Karim Barbhuiya

doi:10.35940/ijeat.d7052.049420

Abstract

This experimental study shows the velocity and turbulence field at vicinity of cylindrical pier with scour hole under clear water condition. The three dimensional velocity data were obtained at 5 cm, 10 cm, 20 cm and 30 cm from the pier with use of Acoustic Doppler Velocimeter at 360 degrees around the pier with 30-degree interval. The flow behaviour were extensively analyzed with the help of time averaged normalized velocity, Turbulent intensity, Turbulent kinetic energy and Reynolds shear stress plots. The study shows the flow behaviour at inside the scour hole, at scour hole ring and outside the scour hole which gives the elusive view of flow at vicinity of pier. An upstream side pier, the flow behaviour almost follows the similar trend but behind a cylinder the flow is asymmetry due to wake vortex and vortex shedding found at the wake region. This study offers an ample cognizance of flow structure at vicinity of circular pier, which is essential in order to design an effective scour control structures like rip-rap, W weir, vanes, slot and etc.,

Highlights

Bridge failure in the river is one of the generic and sensitive issues
From the contour is clearly visible that the scour hole resembles the inverted cone shape and the sediment deposition occurs at 30cm from the downstream of the pier
The velocity and turbulent flow around cylindrical pier with the scour hole under clear water condition was measured with Acoustic Doppler velocimeter (ADV)

Summary

Introduction

Bridge failure in the river is one of the generic and sensitive issues. Failures of bridges and offshore structures are mainly caused by local scour. The flow becomes complex and perturbated when it encountered a vertical obstruction. A large number of experiments were carried out to study the scour phenomena at bridge pier, and they developed an empirical relation for finding scour depth [2]. Prediction of scour depths by those available models is not always accurate due to the sparsity of knowledge of the flow features at the vicinity of piers [3], [4]

Methods

Results

Conclusion