Turbulence Characteristics within the Scour Hole Around Circular Uniform Pier

Local scour around hydraulic structures can lead to their failure. Knowledge of the mechanism of scouring and the prediction of characteristics scour geometry are of great importance during the design of the hydraulic structures. This Paper focused on the measurement of the turbulence surrounding a vertical uniform cylinder in steady flow. The approximate size of the circulations and eddies produced by cylindrical obstacle subjected to steady flow in a rectangular channel are investigated. A three component high sampling frequency Acoustic Doppler Velocimetry(ADV) was used to collect the instantaneous velocity data along the phase angles ranging from 0⁰ to 180⁰ at every 45⁰ interval along the longitudinal and transverse direction. The ADV collected data was filtered by using the Nikora Goring algorithm. Using the filtered data turbulence characteristics were computed. The energy distribution and dependence of fluctuating velocities were determined and interpreted by using spectral analysis technique by generating spectral density functions. Important turbulent characteristics like Reynolds shear stresses, Turbulence Intensity(TI) and Turbulence Kinetic Energy (TKE) for the different phase angles around the circular bridge pier. The experimental investigation related to identifying the coherent structures and wake vortices region around each axis was also carried out in each of the axis. TI and TKE plots for the 0⁰ and 180⁰ planes are also presented in this study.