Experimental investigation on sand bed scour by an oblique planar water jet at varying impinging angles

• Published in: Ocean engineering Vol. 279; p. 114526
• Main Authors: Mao, Jieyun, Si, Jin-Hua, Chen, Jiaqi, Li, Guidong, Wang, Xikun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2023
• Subjects: Impinging angle; Oblique impinging jet; Particle image velocimetry (PIV); Scour hole profiles; Vorticity distribution; Particle image velocimetry (PIV); Scour hole profiles; Vorticity distribution; Oblique impinging jet; Impinging angle
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2023.114526

This study aims to investigate the effects of impinging angle of a planar water jet on the scour hole profiles and flow structure in the scour hole. Based on image recording and Particle Image Velocimetry (PIV) technology, the scour of the oblique planar impinging jet on erodible sand bed is investigated at different impinging angles over the range of 20° ≤ θ ≤ 80°. Time evolution of the scour hole profile was recorded using a video camera, and the flow fields in the scour hole at equilibrium state were measured using PIV. The results show that the normalized maximum dynamic erosion depth εm∞/h is a function of erosion parameter E = F0/h/B. The offset of impinging point on the sand bed from the geometric center is found to decrease with the increase in impinging angle. In addition, the jet width is larger at θ = 30° and 80° than that at θ = 50° for the same value of streamline-wise distance l/B. The present study could give some reference for engineering applications. •The sand scour by an oblique jet was investigated at different impinging angles using Particle Image Velocimetry (PIV).•The empirical equation of maximum dynamic scour depth has been expressed as a function of the impinging angle.•Flow structures have been analyzed to further explain the effect of impinging angles on scour profiles.