The work reported in this thesis mainly involved the development, implementation, and testing of mathematical models and numerical solution methods for computer simulations of temporally and spatially periodic, fully-developed, laminar and turbulent flows in rectangular interrupted-plate ducts. A relatively limited complementary experimental investigation was also undertaken to measure vortex-shedding frcquencies for turbulent flows in the ducts of interest. / The fluid flows considered in this work are characterized by the Reynolds number, Re, and four geometric parameters: The dimensionless streamwise length and half-thickness of the plates, L/H and $ delta /H$, respectively; the nondimensiond streamwise inter-plate spacing, s/H; and the aspect ratio of the rectangular duct cross-section, b/H. Here, H is the half-height of the ducts. In the numerical investigations, it was assumed that $b/H gg 1$ and the fluid flow is two-dimensional. / In the numerical investigation of laminar flows, six different values of the integer periodicity index, m, which refers to the number of geometrically similar modules included in the calculation domain were considered: m = 1, 2 3, 4, 5, and 6. The main findings of this investigation are the following: For $m>1$, multiple stable solutions are possible; the one-module ($m=1$) solution represents one of the possible stable solutions for the multiple-module ($m>1$) calculation domains; the magnitude of the maximum difference between the single- and multiple-module results of the Strouhal number, S, and the time-averaged friction factor, f f, can be as high as 29.2% and 13.9%, respectively; and the critical Reynolds number for the onset of temporally and spatially periodic oscillations increases as the nondimensional plate thickness, $ delta /H$, decreases. It was also found in this investigation that for the thinnest plates considered, $ delta /H$ = 0.12, the numerical solution of the steady-state formulation of the problem provides good estimates of the time-averaged friction factor, f f, and the average nondimensional viscous shear stress, $ tau sbsp{w}{*}$, on the top and bottom surfaces of the plates. However, for $ delta /H$ = 0.20 and 0.32, the unsteady simulations are necessary to obtain accurate values of ff and $ overline{ tau sp{*}} sb{w}$. / It was concluded that at present, a combination of complementary experimental and numerical investigations with fine-tuning of some of the closure coefficients in relatively simple turbulence models such as low-Reynolds number two-equation eddy-viscosity models, may be the most effective approach to the prediction of temporally and spatially periodic, fully-developed turbulent flows in interrupted-surface geometries. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.40245 |
| Date | January 1996 |
| Creators | Sebben, Simone |
| Contributors | Baliga, B. R. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Mechanical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001499037, proquestno: NN12477, Theses scanned by UMI/ProQuest. |
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