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Articles 1 - 6 of 6

Full-Text Articles in Mechanical Engineering

Fixed Bottom Wind Turbine Wave-Wake Interaction, Ondrej Fercak Jul 2021

Fixed Bottom Wind Turbine Wave-Wake Interaction, Ondrej Fercak

Dissertations and Theses

The interest and benefits of offshore wind energy has also brought along legitimate design challenges for engineers. Most notably, the complex interaction between wind and turbine is further complicated by the addition of dynamic ocean waves. This dynamic coupling between wind, wave, and turbine is not fully understood. Even small improvements in wind turbine performance are welcome, so characterizing a fundamental dynamic in offshore energy is necessary to optimize design. Experimentation and simulation have been used to characterize inflow and turbine wakes and separately, wind-wave interactions. But only simulations have just begun to look at the wind, wave, and turbine …


On The Improvements Of Boundary-Layer Representation For High Resolution Weather Forecasting In Costal-Urban Environments, David Melecio-Vazquez Jan 2021

On The Improvements Of Boundary-Layer Representation For High Resolution Weather Forecasting In Costal-Urban Environments, David Melecio-Vazquez

Dissertations and Theses

As large urban centers around the world become more densely populated, the global conversion from natural to man-made land surfaces will only increase. These land-use changes affect the urban surface energy budget which in turn changes the structure of the planetary boundary layer (PBL) above. With current high-performance computing systems, meteorological and built environment information can be better utilized to quantify the anthropogenic effects of these modifications. Although these systems have improved forecasting near-surface weather conditions, a comprehensive approach to represent urban impacts on the PBL is still limited. Improved PBL representation can lead to better weather and climate forecasts, …


Characterization Of Inertial Particles In The Turbulent Wake Of A Porous Disk, Kristin Nichole Travis Jan 2020

Characterization Of Inertial Particles In The Turbulent Wake Of A Porous Disk, Kristin Nichole Travis

Dissertations and Theses

This study presents the findings of a wind tunnel experiment investigating the behaviour of micrometric inertial particles in the turbulent wake of a stationary porous disk. Various concentrations [Φv ∈ (2.95 x 10-6 - 1.22 x 10-5)] of polydisperse water droplets (diameter 13-41 µm) are compared to sub-inertial tracer particles. Hot-wire anemometry, phase Doppler interferometry and particle image velocimetry were implemented in the near and far wake regions to study the complex dynamics of the particles. Turbulence statistics and particle size distributions are presented and used to explore the particle wake interaction.


Infinite Photovoltaic Solar Arrays: Considering Flux Of Momentum And Heat Transfer, Andrew D. S. Glick Jun 2019

Infinite Photovoltaic Solar Arrays: Considering Flux Of Momentum And Heat Transfer, Andrew D. S. Glick

Dissertations and Theses

Large scale solar farms supply an increasing amount of the worlds electricity supply. However, in order to reach cost parity with fossil fuels, further reductions are necessary. Towards this end, photovoltaic (PV) panel cooling becomes increasingly important; high temperatures both decrease efficiency and panel lifetime. To better understand, characterize, and exploit the natural convective cooling of utility scale solar farms, a model solar farm was created. Using both thermal measurements and particle image velocimetry to characterize heat transfer and velocity fields, wind tunnel experiments were conducted using the model solar farm. Three parameters were examined for their effect on heat …


Thermally (Un-) Stratified Wind Plants: Stochastic And Data-Driven Reduced Order Descriptions/Modeling, Naseem Kamil Ali Nov 2018

Thermally (Un-) Stratified Wind Plants: Stochastic And Data-Driven Reduced Order Descriptions/Modeling, Naseem Kamil Ali

Dissertations and Theses

Wind energy is one of the significant sources of renewable energy, yet a number of challenges preclude optimal operation of wind plants. Research is warranted in order to minimize the power losses and improve the productivity of wind plants. Here, a framework combining turbulence theory and data mining techniques is built to elucidate physics and mechanisms driving the energy extraction of the wind plants under a number of atmospheric/operating conditions. The performance of wind turbines is subjected to adverse effects caused by wake interactions. Therefore, it is crucial to understand wake-to-wake interactions as well as wake-to-atmospheric boundary layer interactions. Experimental …


The Determination Of Drag And Lift Forces Of A Rigid Beam Located Within A Turbulent Boindary Layer By Means Of Large Eddy Simulation Modeling, Santiago Helman Jan 2013

The Determination Of Drag And Lift Forces Of A Rigid Beam Located Within A Turbulent Boindary Layer By Means Of Large Eddy Simulation Modeling, Santiago Helman

Dissertations and Theses

"Recent studies such as those conducted by Akaydin, Elvin and Andreopoulos in [1] have described and quantified the electrical power that can be extracted from a moving flow by the implementation of energy harvesters. In such study, a flexible cantilevered beam was fitted with a cylindrical prism at the free end and placed within a uniform flow field. Due to the vortex shedding generated by the prism (e.g. Von Karman vortices) the beam was found to oscillate about the undisturbed position. The beam in question was then outfitted with a piezoelectric material in order to translate the transient strain energy …