Multi-scale statistical characterization of migrating pier scour depth in non-uniform sand bed channel

ABSTRACT

The present study experimentally investigates the multi-scale statistical characterization of migrating pier scour depth over non-uniform sand bed channel. Experiments were conducted for circular piers of 75 mm diameters with and without seepage cases. The results of turbulent flow parameters at the upstream of the pier such as velocity and Reynolds shear stresses (RSSs) are observed to be negative within the scour hole, while the presence of downward seepage counteracts the reversal of the flow results in decreased velocity and Reynolds stresses. RSS is higher at the downstream of the pier owing to the formation of wake vortices. The elevation of scouring is gradually decreased with an increase of time as well as with the increase of downward seepage. Time scale-averaged celerity is decreased with an increase of time and increases with increase of seepage percentage. The present study also investigates the wavelet-based semblance analysis for time series of velocity and bed elevation at different sections of channel, which will show correlations in terms of wavelength and position.

KEYWORDS:

• Celerity
• pier
• seepage
• semblance
• velocity

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Bimlesh Kumar http://orcid.org/0000-0001-6001-8411