Journal article
Gravity current flow past a circular cylinder: forces, wall shear stresses and implications for scour
Journal of fluid mechanics, Vol.649, pp.69-102
04/25/2010
DOI: 10.1017/S002211200999334X
Abstract
The flow of compositional gravity currents past circular cylinders mounted above a wall is investigated numerically. Two- and three-dimensional Navier–Stokes simulations are employed to quantify the force load on the cylinder, along with the friction velocity at the bottom wall near the cylinder, for Reynolds numbers in the range of 2000–45 000. While two-dimensional simulations accurately capture the impact stage, they are seen to overpredict the force and friction velocity fluctuations throughout the transient stage. Comparisons between gravity current and constant-density flows past circular cylinders show that the impact and transient stages are unique to gravity current flows. During the quasi-steady stage, on the other hand, the wake structures and the values of the drag, the peak-to-peak lift, the vortex shedding frequency and the friction velocity below the cylinder are comparable. The friction velocity below the cylinder depends chiefly on the Reynolds number formed with the front velocity and the gap width. The maximum friction velocity at impact is about 60% larger than during the quasi-steady stage or in a constant-density flow. This raises the possibility of aggressive erosion behaviour at impact, which may occur in a spanwise localized fashion because of the larger friction velocity near the lobes.
Details
- Title: Subtitle
- Gravity current flow past a circular cylinder: forces, wall shear stresses and implications for scour
- Creators
- E GONZALEZ-JUEZ - 1Department of Mechanical Engineering, University of California at Santa Barbara, Room 2355, Engineering II Building, Santa Barbara, CA 93106-5070, USAE MEIBURG - 1Department of Mechanical Engineering, University of California at Santa Barbara, Room 2355, Engineering II Building, Santa Barbara, CA 93106-5070, USAT TOKYAY - 2Department of Civil and Environmental Engineering, University of Iowa, 4105 Seamans Center for the Engineering Arts and Sciences, Iowa City, IA 52242, USAG CONSTANTINESCU - 2Department of Civil and Environmental Engineering, University of Iowa, 4105 Seamans Center for the Engineering Arts and Sciences, Iowa City, IA 52242, USA
- Resource Type
- Journal article
- Publication Details
- Journal of fluid mechanics, Vol.649, pp.69-102
- Publisher
- Cambridge University Press; Cambridge, UK
- DOI
- 10.1017/S002211200999334X
- ISSN
- 0022-1120
- eISSN
- 1469-7645
- Number of pages
- 34
- Language
- English
- Date published
- 04/25/2010
- Academic Unit
- Civil and Environmental Engineering
- Record Identifier
- 9983992067702771
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