PIV investigation of turbulent flow around partially submerged circular cylinders with and without simulated upstream ice blocks
| dc.contributor.author | Israel, Mark Kofi | |
| dc.contributor.examiningcommittee | Clark, Shawn (Civil Engineering) | |
| dc.contributor.examiningcommittee | Essel, Ebenezer (Mechanical Engineering) | |
| dc.contributor.supervisor | Tachie, Mark | |
| dc.contributor.supervisor | Dow, Karen | |
| dc.date.accessioned | 2024-08-09T16:52:54Z | |
| dc.date.available | 2024-08-09T16:52:54Z | |
| dc.date.issued | 2024-08-06 | |
| dc.date.submitted | 2024-08-06T17:59:34Z | en_US |
| dc.degree.discipline | Mechanical Engineering | |
| dc.degree.level | Master of Science (M.Sc.) | |
| dc.description.abstract | Two sets of particle image velocimetry (PIV) experiments were conducted around stationary, partially submerged horizontal circular cylinders. The first set investigated the effects of blockage ratio (BR), submergence level, and a simulated upstream ice cover on the spatiotemporal dynamics of the wake flow at a Reynolds number of 10 000. The results were compared to a reference case of a cylinder fully immersed in the uniform flow. Due to the absence of an upper shear layer, the recirculation lengths of the submerged cylinder are longer, but the turbulence levels are lower compared to the uniform case. Increasing BR has no significant effect on the recirculation length but increases turbulence levels. Conversely, a decrease in submergence level shortens the recirculation length but has negligible impact on turbulence levels. An upstream ice cover further reduces the recirculation length and decreases the turbulence levels around the cylinder due to the boundary layer beneath the ice cover. The sources of turbulence production were investigated, and the unsteady dynamics were examined using frequency spectra of fluctuating velocities, proper orthogonal decomposition, and the reverse flow area. The second set of experiments examined the effects of different lengths, thicknesses, and undersurfaces of simulated upstream ice blocks on the mean flow and turbulence transport phenomena around a submerged cylinder. The cylinder was submerged 50% below the free surface, and the Reynolds number was 25 500. The cylinder encounters an approach flow with lower momentum but higher turbulence intensity when placed behind a longer ice block, and undersurface roughness reduces the momentum but enhances the turbulence intensity of the approach flow. The recirculation length, mean velocities, and turbulence levels around the cylinder reduce with increasing ice block length and subsequent roughening of its undersurface. | |
| dc.description.note | October 2024 | |
| dc.identifier.uri | http://hdl.handle.net/1993/38375 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Particle image velocimetry | |
| dc.subject | Partially submerged circular cylinders | |
| dc.subject | Ice blocks | |
| dc.subject | Unsteadiness | |
| dc.subject | Ice block undersurface roughness | |
| dc.title | PIV investigation of turbulent flow around partially submerged circular cylinders with and without simulated upstream ice blocks | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | no | |
| project.funder.name | Manitoba Hydro and NSERC |