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Brian Polagye

Adjunct Investigator

Assistant Professor, Mechanical Engineering





Research Interests

Tidal Energy Site and Device Characterization


Brian Polagye specializes in the characterization of tidal energy sites and devices through his work with the Northwest National Marine Renewable Energy Center. He works closely with Dr. Jim Thomson to develop instrumentation and methodologies to characterize the physical and biological environments at tidal energy sites. A combination of shipboard and stand-alone surveys monitor current velocity, turbulence, water quality, underwater noise, and marine mammal behavior. These activities are essential to the effective siting of tidal energy devices.


2000-present and while at APL-UW

Noise correction of turbulent spectra obtained from acoustic Doppler velocimeters

Durgesh, V., J. Thomson, M. Richmond, and B. Polagye, "Noise correction of turbulent spectra obtained from acoustic Doppler velocimeters," Flow Meas. Instrum., 37, 29-41, doi:10.1016/j.flowmeasinst.2014.03.001, 2014.

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1 Jun 2014

Velocity spectra are essential in characterizing turbulent flows. The Acoustic Doppler Velocimeter (ADV) provides three-dimensional time series data at a single point in space which are used for calculating velocity spectra. However, ADV data are susceptible to contamination from various sources, including instrument noise, which is the intrinsic limit to the accuracy of acoustic Doppler processing. This contamination results in a flattening of the velocity spectra at high frequencies (O(10)Hz).

This paper demonstrates two elementary methods for attenuating instrument noise and improving velocity spectra. First, a "Noise Auto-Correlation" (NAC) approach utilizes the correlation and spectral properties of instrument noise to identify and attenuate the noise in the spectra. Second, a Proper Orthogonal Decomposition (POD) approach utilizes a modal decomposition of the data and attenuates the instrument noise by neglecting the higher-order modes in a time-series reconstruction. The methods are applied to ADV data collected in a tidal channel with maximum horizontal mean currents up to 2 m/s. The spectra estimated using both approaches exhibit an f-5/3 slope, consistent with a turbulent inertial sub-range, over a wider frequency range than the raw spectra. In contrast, a Gaussian filter approach yields spectra with a sharp decrease at high frequencies.

In an example application, the extended inertial sub-range from the NAC method increased the confidence in estimating the turbulent dissipation rate, which requires fitting the amplitude of the f-5/3 region. The resulting dissipation rates have smaller uncertainties and are more consistent with an assumed local balance to shear production, especially for mean horizontal currents less than 0.8 m/s.

Integrated instrumentation for marine energy monitoring

Polagye, B., J. Joslin, A. Stewart, and A. Copping, "Integrated instrumentation for marine energy monitoring," Proc., 2nd International Conference on Environmental Interactions of Marine Renewable Energy Technologies (EIMR 2014), 28 April - 2 May, Stornaway, Isle of Lewis, Scotland (2014).

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28 Apr 2014

Integrated instrumentation packages designed for operation at marine renewable energy sites have the potential to reduce the risk uncertainty around high- priority interactions between stressors and receptors. Such packages can leverage the competitive strengths of individual instruments and reduce risk in a rapid, cost-effective manner. One emerging example of environmental infrastructure to achieve these objectives, the Adaptable Monitoring Package, is presented and its capabilities described. The development and adoption of such packages requires close coordination between resource managers, technology developers, and researchers.

Development of an adaptable monitoring package for marine renewable energy projects. Part II: Hydrodynamic performance

Joslin, J., B. Polagye, A. Stewart, and B. Rush, "Development of an adaptable monitoring package for marine renewable energy projects. Part II: Hydrodynamic performance," Proc., 2nd Marine Energy Technology Symposium (METS 2014), 15-18 April, Seattle, WA (2014).

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15 Apr 2014

The Adaptable Monitoring Package (AMP), along with a remotely operated vehicle (ROV) and custom tool skid, is being developed to support near-field (≤ 10 meters) monitoring of hydrokinetic energy converters. The AMP is intended to support a wide range of environmental monitoring in harsh oceanographic conditions, at a cost in line with other aspects of technology demonstrations. This paper, which is the second in a two part series, covers the hydrodynamic analysis of the AMP and deployment ROV given the strong waves and currents that typify marine renewable energy sites. Hydrodynamic conditions from the Pacific Marine Energy Center's wave test sites (PMEC) and Admiralty Inlet, Puget Sound, Washington are considered as early adoption case studies. A methodology is presented to increase the AMP's capabilities by optimizing its drag profile through a combination of computational fluid dynamic (CFD) modeling and sub-scale experiments. Preliminary results suggest that AMP deployments should be possible in turbulent environments with a mean flow velocity up to 1 m/s.

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In The News

AMPing up underwater environmental monitoring

UW News, Chelsea Yates

Researchers have long been interested in better understanding how marine energy affects underwater environments, and thanks to UW engineers, they may be a big step closer.

26 Jul 2017

"Millennium Falcon" launches "X-Wing" into marine world

Marine Technology News, Eric Haun

The long-term effect of renewable energy installations on marine animals is to be investigated by researchers at Washington University. APL-UW Ocean Engineers Andy Stewart, Ben Rush, Paul Gibbs, Trina Litchendorf, Tim McGinnis, and Chris Siani are involved in this R&D project.

5 May 2015

New tool monitors effects of tidal, wave energy on marine habitat

UW News and Information, Michelle Ma

A new robot will deploy instruments to gather information in unprecedented detail about how marine life interacts with underwater equipment used to harvest wave and tidal energy.

5 Feb 2015

More News Items


An Adaptable Monitoring Package for Marine Environmental Monitoring

Record of Invention Number: 47352

Brian Polagye, James Joslin, Ben Rush, Andy Stewart


21 May 2015

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center