Ocean Engineering Commons^™

Simulating The Effects Of Floating Platforms, Tilted Rotors, And Breaking Waves For Offshore Wind Turbines, Hannah Johlas

Doctoral Dissertations

Offshore wind energy is a rapidly expanding source of renewable energy worldwide, but many aspects of offshore wind turbine behavior are still poorly understood and are not accurately captured by low-cost engineering models used in the design process. To help improve these models, computational fluid dynamics (CFD) can provide valuable insight into the complex fluid flows that affect offshore wind turbine power generation and structural loads. This research uses CFD simulations to examine three main topics important to future offshore wind development: how breaking waves affect structural loads for fixed-bottom wind turbines; how platform motions affect power generation, wake characteristics, …

Complicating Factors In Hydraulic Jumps: The Effects Of Earth's Rotation, Muveno Pascoal Elias Mucaza

Electronic Thesis and Dissertation Repository

Hydraulic jumps at the interface of stratified rotating fluids are studied. The flow is de- fined with continuous density and velocity profiles, with the velocity in each layer changing (upstream shear). The study is conducted in jumps defined by an imposed velocity transition, and jumps developing over a topography.

The numerical simulations conducted showed the qualitative structure of the flow changing in the cross-width direction, as well as the size and amount of turbulence of the jumps. Mixing in these jumps was shown to increase towards the side of the domain where the jumps were larger and more turbulent. The …

Study Of The Mechanlsm Of Flow-Induced Vibrations Of A Cylinder In Proximity To A Wall, Jonathan M. Chambers

Master’s Theses

Flexible bluff bodies exposed to a uniform fluid flow undergo vibration due to vortex-shedding from the body. This phenomenon is known as vortex-induced vibration (VIV). Structural members, such as cables, conduits, and pipes, are susceptible to VIV. Vortex-induced vibrations result in structural stresses due to elastic structural deformation from the flow-induced loading. Cylindrical structures in proximity to planar surfaces can undergo vortex-induced vibrations when the gap between the cylinder and the planar surfaces is above a critical value. This laboratory study investigated the mechanism of vibration and planar wall proximity effect on the cylinder response to the vortex shedding process. …