Engineering Commons^™

Fundamental Study And Development Of Tuned Active Flow Control Actuators, Brian A. Binkley

Doctoral Dissertations

A novel, multi-level, flow-control actuator was developed using piezoceramic materials. Several actuators were fabricated in various shapes and sizes to produce a variety of effects for flow control applications. The actuators were studied in a quiescent-air bench test to understand the vibrations produced by various actuator shapes. The actuator flow-control effect was studied experimentally with flat-plate and cavity configurations, and was studied numerically using moving boundary conditions and dynamic meshing. The disturbances produced by the actuator couple with the cavity flow field producing increased cavity tones, increased vorticity, and sustainment of large-scale vorticity downstream of the cavity. The combined actuation …

Computational Thermal-Hydraulics Modeling Of Twisted Tape Enabled High Heat Flux Components, Emily Buckman Clark

Doctoral Dissertations

The goal of this work was to perform a computational investigation into the thermalhydraulic performance of water-cooled, twisted tape enabled high heat flux components at fusion relevant conditions. Fusion energy is a promising option for future clean energy generation, but the community must overcome significant scientific and engineering challenges before meeting the goal of electricity generation. One such challenge is the high heat flux thermal management of components in fusion and plasma physics experiments. Plasma facing components in the magnetic confinement devices, such as ITER or W7-X, will be subjected to extreme heat loads on the order of 10-20 MW/m …

Improving Predictive Capabilities Of Classical Cascade Theory For Nonproliferation Analysis, David Allen Vermillion

Doctoral Dissertations

Uranium enrichment finds a direct and indispensable function in both peaceful and nonpeaceful nuclear applications. Today, over 99% of enriched uranium is produced by gas centrifuge technology. With the international dissemination of the Zippe archetypal design in 1960 followed by the widespread illicit centrifuge trafficking efforts of the A.Q. Khan network, traditional barriers to enrichment technologies are no longer as effective as they once were. Consequently, gas centrifuge technology is now regarded as a high-priority nuclear proliferation threat, and the international nonproliferation community seeks new avenues to effectively and efficiently respond to this emergent threat.

Effective response first requires an …