Thesis (Ph. D.)--Columbia University, 1941. / Cover title. Some pages numbered as leaves. Reproduced from type-written copy. Vita. Bibliography: p. [4-7] at end.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph. D.)--University of Washington, 1987. / Vita. Bibliography: leaves [228]-236.

Drop impacts are ubiquitous in nature forming a vital pathway for the transport of liquids, primarily water, and any dissolved substances. The axisymmetric impact of drops has been heavily studied but less work has been done on droplet impacts in which axial symmetry is broken. To analyse such impacts we used a two phase lattice Boltzmann code capable of simulating high density differences. We studied the impact of droplets on cylindrical surfaces, with radius of curvature similar to that of the drop. We found that the symmetry breaking nature of these surfaces leads to droplets bouncing faster and in elongated shapes. The origin of this effect is a positive feedback mechanism through which the momentum asymmetry resulting from the impact grows during retraction. We next looked at how varying the size of the cylinder affected this phenomenon. We found that smaller cylinders increased the contact time reduction, as long as they were still bigger than the droplet, but that below this limit the drop contacted the flat surface and entered a new regime. The work was expanded to look at other types of bouncing asymmetry, using a simple, exactly solvable Lagrangian model. We found that contact time reduction can result from an asymmetric droplet shape, an initially asymmetric velocity or if the surface has an asymmetric drag. A study of the impact of liquid drops containing embedded air bubbles was also undertaken. This was found to lead to jet formation from the bottom of the bubble. We showed how the jet velocity depended on the physical parameters of the drop and impact. In particular the jet formation was very sensitive to the position of the air bubble inside the drop.

Culverts are designed to carry water from one side of an embankment to another. There are many culverts under a typical highway and they add significantly to its cost. The hydraulic design of a culvert is surprisingly complex and since its primary purpose is to convey water, it is important that it has the full intended flow capacity. The objective of this thesis was to develop a computer program to help an engineer with the hydraulic design of culverts. The user of the program can choose between designing a new culvert or checking the adequacy of an existing culvert from a hydraulic, point of view. The program handles the problem of sediment deposition that can occur and reduce the capacity of culverts having gentle slopes. The most widely used culvert shapes are included in the program and in this thesis. Comments are provided on the conditions under which certain shapes are best. Culvert inlets are given, and some improved inlet designs are presented since the inlet design can have a major impact on the cost of the culvert. Also, erosion at the culvert outlet is discussed and suggestions are provided on how to prevent it or cope with it. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Hydrodynamics interaction is a factor in the performance of fish schooling or underwater vessels in close formation. In this work, we visualized the wake structure of pitching hydrofoils using an inclined soap film. We considered one-, two-, three- and nine-foil configurations with different spacing and actuation parameters: amplitude (A), frequency (f), phase difference (), and flow speed (U). The wake structures were recorded with a high-speed camera and analyzed to measure the vortex angle created. The wake structure of two- and three-foil configurations were compared with the Strouhal number, St = fA/U, of a single foil. For the nine-foil configuration, the wake velocity and the standard deviation of the velocity were used to interpret the hydrodynamic interaction. It was found that both spacing and phase difference between foils are relevant in the hydrodynamic interaction. Qualitative observations are also made, and vortex street behavior characteristics are identified. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

No description available.

No description available.

Graduation date: 1998

[Truncated abstract] Coastal lagoons play an important role in the transport of materials between the coastal zone and the ocean. Understanding the dynamics associated with the movement of waters between and within these systems is therefore significant in defining the ecological health of the system. An important sub category of lagoons is Intermittently Closing and Opening Lakes and Lagoons (ICOLLs). These systems lack any significant river inflow; have a restricted sill type inlet and experience intermittent exchange with the ocean, making them susceptible to the retention of nutrients and pollutants from the catchment. The duration and frequency of an opening event may vary from weeks to months between each ICOLL, and inter and intra annually, respectively, and during an opening event, there are appreciable fluctuations in water level (1-3m range) accompanied by large changes in salinity (7 30ppt) within a short timeframe (hours). . . Regardless of the processes complete oceanic flushing was still predicted for each system, by the end of their respective opening events. The modelling work successfully reproduced the spring tidal setup in water level and exchange, using real bathymetry and meteorological forcing and defined the spring tidal set-up as the key predictable process in the exchange of water and salt between the larger ICOLL and the ocean. It was also shown that strong winds had the capacity to influence the magnitude of the exchange. The overall outcomes of this research therefore include the identification of key physical processes associated with the variability of the hydrodynamics within and between ICOLLs, which will aid in the future management of these highly dynamic systems.