자료유형  

 학위논문

Control Number  

0016932910

International Standard Book Number  

9798379879648

Dewey Decimal Classification Number  

620

Main Entry-Personal Name  

Abney, Andrew Daniel.

Publication, Distribution, etc. (Imprint  

[S.l.] : North Carolina State University., 2023

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2023

Physical Description  

1 online resource(125 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 85-01, Section: B.

General Note  

Advisor: Buckner, Gregory;Mazzoleni, Andre;Bryant, Matthew;Husain, Iqbal;Vermillion, Chris.

Dissertation Note  

Thesis (Ph.D.)--North Carolina State University, 2023.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Summary, Etc.  

요약Over recent decades, there has been a great interest in harnessing ocean current energy resources in order to generate meaningful electricity, both at utility scales, and for applications within the so-called "blue economy", the latter of which entails providing supplemental power to maritime vessels, or to enable persistent autonomous research vessel missions. This work explores the application of marine hydrokinetic (MHK) kites anchored to the seabed as a mechanism for harnessing resources located near the surface in regions where the ocean depth is on the order of kilometers. Reaching these resources from the seabed requires operating an MHK kite on tether lengths which have never been considered in the literature. Resources such as the Gulf Stream off the coast of North Carolina are of particular interest due to the relatively stable flow profile combined with flow velocities frequently exceeding 1 m/s; in fact, this resource serves as a primary motivation for this work. In order to harvest meaningful power however, novel control algorithms that mitigate the trade-offs inherent in operating at the altitudes required to reach the flow resource from the seabed in the region around the Gulf Stream will be required.This dissertation focuses on the developing control methodologies that enable ultralong tethered (ULT) kites to generate power sufficient power levels despite the difficulties of operating on ultra-long tethers. Accurate prediction of system performance is a prerequisite for such optimizations to carry any functional use. To that end, this work first presents a summary of an extensive experimental campaign, which provided the first example of an open-source platform to achieve autonomous control for a MHK kite and provided extensive model validation. Following that, a feasibility study is conducted for ultra-long tether applications, including a characterization of the contribution of tether drag and shear layer effects on the performance of MHK kite systems. This study demonstrates that a well designed path reduces the impact of tether drag on a kite system. This work then develops a novel formulation of the power coefficient of an MHK kite as a function of angle of attack, tether drag coefficient, and turbine rotor angular velocity profile. Finally, an indirect adaptive control law is developed, termed switching economic iterative learning control (se-ILC), which optimizes an objective cost while enabling intelligent navigation of coupled design spaces. This extends previous results in the literature by specifically accounting for parameter coupling in the objective function, which results in improved convergence properties over existing methodologies. Switching economic iterative learning control is then applied to the problem of ULT kites, wherein the coupled design space of path geometry and turbine rotor profile are optimized in order to maximize lap averaged power. In each case tested, se-ILC demonstrated improved economic performance relative to methodologies established in the literature.

Subject Added Entry-Topical Term  

Turbines.

Subject Added Entry-Topical Term  

Control algorithms.

Subject Added Entry-Topical Term  

Ocean currents.

Subject Added Entry-Topical Term  

Flow velocity.

Subject Added Entry-Topical Term  

Energy resources.

Subject Added Entry-Topical Term  

Parameter identification.

Subject Added Entry-Topical Term  

Ground stations.

Subject Added Entry-Topical Term  

Sensors.

Subject Added Entry-Topical Term  

Altitude.

Subject Added Entry-Topical Term  

Aerospace engineering.

Subject Added Entry-Topical Term  

Energy.

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Fluid mechanics.

Subject Added Entry-Topical Term  

Mechanics.

Subject Added Entry-Topical Term  

Physical oceanography.

Subject Added Entry-Topical Term  

Statistics.

Added Entry-Corporate Name  

North Carolina State University.

Host Item Entry  

Dissertations Abstracts International. 85-01B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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Control Number  

joongbu:641784