Record Details
Field | Value |
---|---|
Title | A study of turbulence in the viscous sublayer and logarithmic region of the bottom boundary layer |
Names |
Chriss, Terry Michael
(creator) Caldwell, D. R. (advisor) |
Date Issued | 1981-09-04 (iso8601) |
Note | Graduation date: 1982 |
Abstract | Detailed current profiles between the sediment-water interface and 20 cm above it reveal a viscous sublayer in the bottom boundary layer on the Oregon continental shelf. Data from three field experiments are used to test fundamental assumptions about boundary layer flow in the ocean. The first study, discussed in Chapter 1, evaluates the hypothesis that, in the absence of the obvious influence of topographic irregularities, the flow behaves like a universally similar, neutrally-buoyant flow over a smooth wall. The second study, discussed in Chapter 2, evaluates the influence which irregular small-scale topography may have on the near-bed flow, while the third, discussed in Chapter 3, examines streamwise velocity fluctuations in the viscous Sublayer and buffer layer and evaluates the hypothesis that spectra from the viscous sublayer and buffer layer of laboratory and geophysical boundary layer flows can be reduced to universal forms. although the thickness of the viscous sublayer scales with v/u, as required by universal similarity, the non-dimensional sublayer thickness is not as constant as in neutrally-buoyant laboratory flows. Even in the absence of the obvious effects of bottom irregularities, the near-bed flow is not as simple as smooth-walled boundarylayer flows in the laboratory. In the second study, it is shown that when the near-bed flow experiences resistance due to form drag as well as skin friction, the constant stress boundary layer assumption is not valid close to the sediment-water interface. Th the third study, it is shown that non-dimensionalized spectra of streamwise velocity fluctuations in the viscous sublayer and buffer layer at the ocean floor are very similar to those found in the laboratory. |
Genre | Thesis/Dissertation |
Topic | Turbulent boundary layer |
Identifier | http://hdl.handle.net/1957/28118 |