Date of Award

2024

Degree Type

Thesis

Degree Name

Master of Science in Ocean Engineering

Department

Ocean Engineering

First Advisor

Jason Dahl

Abstract

Acoustic metamaterials (AMs) have been proposed for uses in flow control, as they offer a passive control method and can be engineered independently, without needing complex fluid structure interactions simulations. For example, AMs embedded into flat plate surfaces have been demonstrated to delay (or speed up) the onset of laminar-to-turbulent boundary layer transition by attenuating (or strengthening) Tollmein-Schlicting waves through numerical simulation. However, as of present, no experimental research has been conducted to study or demonstrate the behaviors of AMs designed to interact with flow structures. An experiment was performed in which an AM was embedded into a flat plate with a circular cylinder positioned near the surface upstream to generate oscillatory flow instabilities at a controlled frequency. The effectiveness of the AM to attenuate the artificially introduced instability waves from the vortices shed off of the cylinder was evaluated over a range of flow speeds, vortex shedding frequencies, and cylinder positions using measurements made with 2-D particle image velocimetry. It was found that the AM could successfully attenuate instabilities with the target frequency band and affect the wake of the cylinder in certain conditions.

Comments

Controlled Unclassified Information (CUI) has been removed from thesis PDF.

Available for download on Saturday, September 12, 2026

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