Biography

Brian Polagye is a Professor in the Department of Mechanical Engineering. His research focuses on marine renewable energy conversion and its environmental effects, with the ultimate goal of developing cost-effective, sustainable approaches. He is also an Affiliate Investigator with the Applied Physics Laboratory and holds a dual appointment with Pacific Northwest National Laboratory.

Education

• Ph.D. in Mechanical Engineering, University of Washington, 2009
• M.S. in Mechanical Engineering, University of Washington, 2005
• B.S. in Mechanical Engineering, Princeton University, 2000

Research Statement

Brian Polagye's research group focuses on the conversion of marine renewable energy resources (river, tidal, and ocean currents, as well as waves) to mechanical power. One thrust area is optimizing the hydrodynamics and control of current turbines and wave energy converters, primarily through laboratory experiments. A second thrust area is developing and applying instrumentation necessary to characterize marine energy sites, with emphasis on underwater sound.

Current research topics include:

• Studying the hydrodynamics of cross-flow current turbines to increase individual turbine and array power yields
• Studying the hydrodynamics and control of wave energy converters, with an emphasis on the hull geometry
• Measuring the acoustic characteristics of marine energy converters

Current projects

Confinement-exploiting Cross-flow Turbines
With support from ARPA-E, a team of researchers from UW, University of Wisconsin, and the National Renewable Energy Laboratory are exploring the extent to which confinement (the ratio of turbine projected area to channel cross-sectional area) can substantially reduce the cost of energy for arrays of tidal current turbines. It is well established that confinement increases a turbine's power coefficient, allowing it to exceed the Betz limit, but confinement also increases structural forces, which is an economic penalty. The project combines experiments with turbine arrays, flow-field characterization, numerical simulation, and techno-economic modeling to demonstrate cost of energy reductions of > 50%.

Wave Energy Converter Hull Geometry

The overall performance of wave energy converters (WECs) depends on the coupled response of the prime mover and incident wave field. While the influence of hull geometry has been explored through linear modeling methods, there is a limited experimental knowledge base. This project seeks to address this gap for surface-piercing and sub-surface WECs.

Effects of Inclined Inflow on Cross-flow Turbines

Cross-flow (or vertical-axis) turbines have the unique property of rotating in the same direction, regardless of current direction in the horizontal plane. However, unlike axial-flow turbines, there is not yet an empirical or analytical theory that describes how power production and structural loads change when currents have a significant out-of-plane component. This research, conducted in collaboration with Owen William's research group, seeks to address this knowledge gap through experimental performance measurements and near-blade flow visualization.

Select publications

1. Snortland, A., Hunt, A., Williams, O., & Polagye, B. (2025) Influence of the downstream blade sweep on cross-flow turbine performance. Journal of Renewable and Sustainable Energy, 17 (1), doi: 10.1063/5.0230563
2. Polagye, B., Crisp, C., Jones, L., Murphy, P., Noe, J., Calandra, G., & Bassett, C. (2024) Performance of a Drifting Acoustic Instrumentation SYstem (DAISY) for characterizing radiated noise from marine energy converters. Journal of Ocean Engineering and Marine Energy, doi: 10.1007/s40722-024-00358-6
3. Hunt, A., Strom, B., Talpey, G., Ross, H., Scherl, I., Brunton, S., Wosnik, M., & Polagye, B. (2024) A parametric evaluation of the interplay between geometry and scale on cross-flow turbine performance. Renewable and Sustainable Energy Reviews, 206, doi:10.1016/j.rser.2024.114848
4. Ross, H., & Polagye, B. (2022). Effects of dimensionless parameters on the performance of a cross-flow current turbine. Journal of Fluids and Structures, 114, 103726.
5. Strom, B., Polagye, B., & Brunton, S. L. (2022). Near-wake dynamics of a vertical-axis turbine. Journal of Fluid Mechanics, 935.
6. Dillon, T., Maurer, B., Lawson, M., Jenne, D. S., Manalang, D., Baca, E., & Polagye, B. (2022). Cost-optimal wave-powered persistent oceanographic observation. Renewable Energy, 181, 504-521.
7. Cotter, E. & Polagye, B. (2020) Automatic classification of biological targets in a tidal channel using a multibeam sonar. Journal of Atmospheric and Oceanic Technology. doi:10.1175/JTECH-D-19-0222.1
8. Polagye, B., Joslin, J., Murphy, P., Cotter, E., Scott, M., Gibbs, P., Bassett, C., & Stewart, A. (2020) Adaptable Monitoring Package development and deployment: Lessons learned for integrated instrumentation at marine energy sites. Journal of Marine Science and Engineering, 8, 553. doi:10.3390/jmse8080553
9. Harrison, T., Thyng, K., & Polagye, B. (2020) Comparative evaluation of volumetric current measurements in a tidally-dominated, coastal setting: a virtual field experiment. Journal of Atmospheric and Oceanic Technology, 37 (4): 533–552. doi:10.1175/JTECH-D-19-0131.1
10. Ross, H. & Polagye, B. (2020) An experimental assessment of analytical blockage corrections for turbines. Renewable Energy, 152. doi: 10.1016/j.renene.2020.01.135
11. Polagye, B., Strom, B., Ross, H., Forbush, D., & Cavagnaro, R. (2019) Comparison of cross-flow turbine performance under torque-regulated and speed-regulated control, Journal of Renewable and Sustainable Energy, 11(4). doi: 10.1063/1.5087476
12. Strom, B., Brunton, S., & Polagye, B. (2017). Intracycle angular velocity control of cross-flow turbines. Nature Energy, 2, doi: 10.1038/nenergy.2017.103.
13. Forbush, D., Polagye, B., Thomson, J., Kilcher, L., Donegan, J., & McEntee, J. (2016). Performance characterization of a cross-flow hydrokinetic turbine in sheared inflow. International Journal of Marine Energy, 16, 150-161.
14. Cavagnaro, R. & Polagye, B. (2016) Field performance assessment of a hydrokinetic turbine. International Journal of Marine Energy, doi: 10.1016/j.ijome.2016.01.009.
15. Bassett, C., Thomson, J., Dahl, P. H., & Polagye, B. (2014). Flow-noise and turbulence in two tidal channels. The Journal of the Acoustical Society of America, 135(4), 1764-1774. doi:10.1121/1.4867360.
16. Polagye, B., & Thomson, J. (2013). Tidal energy resource characterization: methodology and field study in Admiralty Inlet, Puget Sound, WA (USA). Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 227(3), 352-367. doi:10.1177/0957650912470081
17. Bassett, C., B. Polagye, M. Holt, & J. Thomson (2012). A vessel noise budget for Admiralty Inlet, Puget Sound, Washington (USA). J. Acoust. Soc. Am., 132(6), 3706-3719.
18. Thomson, J., B. Polagye, V. Durgesh, & M. Richmond (2012). Measurements of turbulence at two tidal energy sites in Puget Sound, WA (USA), IEEE J. Ocean. Eng., 37(3), 363-374.
19. Polagye, B., Kawase, M., & Malte, P. (2009). In-stream tidal energy potential of Puget Sound, Washington, Proc. IMechE, Part A: J. Power and Energy, 223(5).
20. Polagye, B., Malte, P., and Hodgson, K. (2007) An economic analysis of bio-energy options using thinnings from overstocked forests, Biomass and Bio-energy, 31(2-3)

Honors & awards

• College of Engineering Junior Faculty Award, 2015

News