Aerospace Engineering Commons^™

Sediment Resting, Entrainment And Depositional Patterns In A Gravel Bed: Connecting Bedload Transport With Turbulence Structure, Micah Alan Wyssmann

Doctoral Dissertations

This research is founded on the consideration that bedload transport in gravel-bed rivers is interrelated in many ways with turbulence structure. As such, the research includes semi-theoretical modeling and open-channel flume experimental studies that improve our understanding of bedload transport by incorporating knowledge about turbulence, in addition to improving our fundamental knowledge about turbulence.

The first study focused on sediment resting time, which is a minimally understood component of sediment virtual velocity. A semi-theoretical model for resting time that considers momentum transfer from near-bed turbulence was developed, calibrated, and verified. The formulation also included parameters that consider sediment size nonuniformity …

Lattice Boltzmann Methods For Wind Energy Analysis, Stephen Lloyd Wood

Doctoral Dissertations

An estimate of the United States wind potential conducted in 2011 found that the energy available at an altitude of 80 meters is approximately triple the wind energy available 50 meters above ground. In 2012, 43% of all new electricity generation installed in the U.S. (13.1 GW) came from wind power. The majority of this power, 79%, comes from large utility scale turbines that are being manufactured at unprecedented sizes. Existing wind plants operate with a capacity factor of only approximately 30%. Measurements have shown that the turbulent wake of a turbine persists for many rotor diameters, inducing increased vibration …

An Automated Finite Element Analysis Framework For The Probabilistic Evaluation Of Composite Lamina Properties, Jonathan Phillips Weigand

Masters Theses

This thesis outlines the development of computational modeling tools used to predict the elastic properties of composite lamina from representative volume elements (RVE) using numerical methods. The homogenization approach involves the use of Gauss’s Theorem to simply the average volumetric strain integral into a surface integral containing which is defined by surface displacements and their direction. Simulations of RVEs under specific loading conditions (longitudinal tension or shear and transverse tension or shear) are then performed in the software package ABAQUS to obtain the surface displacements. It was found that obtaining quality meshes and applying periodic boundary conditions for each RVE …