摘要：In this study, the fractal dimensions of velocity fluctuations and the Reynolds shear stresses propagation
for flow around a circular bridge pier are presented. In the study reported herein, the fractal dimension of
velocity fluctuations (u0
, v0
, w0
) and the Reynolds shear stresses (u0
v0 and u0
w0
) of flow around a bridge
pier were computed using a Fractal Interpolation Function (FIF) algorithm. The velocity fluctuations of
flow along a horizontal plane above the bed were measured using Acoustic Doppler Velocity meter (ADV)
and Particle Image Velocimetry (PIV). The PIV is a powerful technique which enables us to attain high
resolution spatial and temporal information of turbulent flow using instantaneous time snapshots. In this
study, PIV was used for detection of high resolution fractal scaling around a bridge pier. The results
showed that the fractal dimension of flow fluctuated significantly in the longitudinal and transverse
directions in the vicinity of the pier. It was also found that the fractal dimension of velocity fluctuations
and shear stresses increased rapidly at vicinity of pier at downstream whereas it remained approximately
unchanged far downstream of the pier. The higher value of fractal dimension was found at a distance
equal to one times of the pier diameter in the back of the pier. Furthermore, the average fractal
dimension for the streamwise and transverse velocity fluctuations decreased from the centreline to the
side wall of the flume. Finally, the results from ADV measurement were consistent with the result from
PIV, therefore, the ADV enables to detect turbulent characteristics of flow around a circular bridge pier.
