Aerospace Engineering Commons^™

Analysis Of Multiple Degree-Of-Freedom Oscillatory Aquatic Propulsion, Seth Alan Brooks

Dissertations - ALL

Propulsive performance and flow field data were experimentally measured for a two degree-of-freedom fish platform. The fish platform was designed and constructed based on the yellowfin tuna (\textit{Thunnus albacares}) that is known to be both fast and efficient. This work extends the current understanding of oscillatory aquatic propulsion to a three-dimensional fish platform with full volume flow field data and propulsive performance. A parametric sweep of trailing-edge amplitude of the caudal fin ($A$), heave-to-pitch ratio ($h^*$), and phase offset between the two degrees-of-freedom ($\phi$) was used to explore a parameter space that encompasses and extends beyond the known biological domain. …

Flow Interaction Between Turbomachine Blade Row And Flow Resistance Medium, Tong Lin

Dissertations - ALL

This research investigates the fluid-dynamic interaction between close-coupled axial turbomachines and surrounding components, e.g., heat-exchangers, filters, or cooling fins in high-density computer servers, and its effects on turbomachine and system performance. The importance of this research is that the flow interaction effect occurs in every scenario that requires system compactness.

Firstly, a combined experimental and 3-D computational study on an off-the-shelf server cooling fan is performed, showing that the fan performance has little changed. However, the system performance can be very different since the server cooling has a large hub-to-tip radius ratio, which effectively blocks the high resistance media's (HRM) …