Date of Award
2006
Degree Type
Thesis
Degree Name
Master of Engineering Science
Program
Civil and Environmental Engineering
Supervisor
Dr. Gregory A. Kopp
Second Advisor
Dr. Roi Gurka
Abstract
Au experimental study using Particle Image Velocimetry (PIV) to investigate the |influence of (bluff) body geometry on the flow around elongated cylinders with distinct leading and trailing edge geometries in smooth uniform flow was completed at Reynolds number of 3xl04. The physical details of the leading edge play a significant role in controlling the strength of initial separation, the size of the separation bubble adjacent to the body, the pressure fluctuations exhibited at the point of reattachment along the body and the quality of the boundary layer at the trailing edge. The model elongation ratio, in conjunction with the influence of the leading edge, has a profound impact on the interaction of leading-edge and trailing-edge vortices. The rectangular cylinder, included among the four geometries examined in this study, did not have a periodic vortex street, but did have coherent lift fluctuations at a frequency of 105Hz (St = 0.15) found via power spectral analysis of the fluctuating lift forces. The remaining models did produce vortex streets which were observed to be quite sensitive to the body geometry, in particular the trailing edge. This resulted in alternate fluctuating lift forces on the bodies. The turbulent wake behaviour of the four models was investigated to highlight its influential role on the coherent structures produced. The many subtleties of vortex shedding were made apparent, which provided evidence to support that this phenomenon cannot be characterized by a single parameter, such as the Strouhal number
Recommended Citation
Palombi, Emanuela, "EFFECTS OF GEOMETRY ON THE FLOW AROUND ELONGATED CYLINDERS" (2006). Digitized Theses. 5084.
https://ir.lib.uwo.ca/digitizedtheses/5084
