Turbulent bursting events within equilibrium scour holes around aligned submerged cylinder

ABSTRACT

The effect of cylinder alignment on the turbulent bursting events and sediment entrainment around submerged circular and square cylinder within the scour hole are investigated in the present study. The quadrant analysis technique was employed to establish a correlation between the bursting events and the resulting coherent turbulent structures that affect the sediment entrainment process. The results indicate the existence of a strong horseshoe vortex system and excessive sediment entrainment within the equilibrium scour hole. The dominant longitudinal velocity component increases with the increase of the alignment angle of the square cylinders. The spectral analysis shows that the peak of power spectra and vortex shedding frequency decreases with the increase of the height of the cylinder. Also, the quadrant analysis of the bursting events shows that the Reynolds shear stress increases with the increase of hole size for the interaction events. The range of contributions of stress fraction towards the ejection and sweep events significantly increases with the increase of hole size.

KEYWORDS:

• Submerged cylinders
• angle of alignment
• quadrant analysis
• bursting events
• Reynolds stress

Acknowledgment

The authors gratefully acknowledge the suggestions and comments of the editor and the reviewers, which helped the authors to prepare a much better version of the revised manuscript. The authors are also thankful to the Department of Science and Technology, Government of India for funding the project (Grant No: SR/S3/MERC/0029).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors gratefully acknowledge the suggestions and comments of the editor and the reviewers, which helped the authors to prepare a much better version of the revised manuscript. The authors are also thankful to the Department of Science and Technology, Government of India for funding the project (Grant No: SR/S3/MERC/0029).