Publications

Proportional Control of Aerodynamic Forces Using an Active Gurney Flap on a Wind Turbine Blade Section

Published in Wind Energy, 2025

Real-time, proportional deployment of an active Gurney flap near the trailing edge of a wind turbine blade section is used to modulate lift and pitching moment, with the aerodynamic response scaling with deployment angle.

Recommended citation: S. Hao, A. Koh-Bell, R. Irani, J. Kirsch-Posner, K. Breuer. Proportional Control of Aerodynamic Forces Using an Active Gurney Flap on a Wind Turbine Blade Section [J]. Wind Energy, 2025, 28(10): e70056. https://doi.org/10.1002/we.70056

Upstroke Wing Clapping in Bats and Bat-Inspired Robots Offers Efficient Lift Generation

Published in Journal of the Royal Society Interface, 2025

Experiments with bats and a bat-inspired flapping robot show that clapping the wings during the upstroke enhances lift generation while improving power economy.

Recommended citation: X. Fan, A. Bortoni, S. Hao, S. Swartz, K. Breuer. Upstroke wing clapping in bats and bat-inspired robots offers efficient lift generation [J]. Journal of the Royal Society Interface, 2025, 22(223): 20240590. https://doi.org/10.1098/rsif.2024.0590

It Pays to Follow the Leader: Metabolic Cost of Flight is Lower for Trailing Birds in Small Groups

Published in Proceedings of the National Academy of Sciences, 2024

Combining wind tunnel flight tests, kinematic tracking and metabolic measurements on European Starlings to quantify the energetic benefit of trailing positions in small flocks.

Recommended citation: S. I. Friman, C. R. Elowe, S. Hao, L. Mendez, R. Ayala, I. Brown, C. Hagood, Y. Hedlund, D. Jackson, J. Killi, G. Orfanides, E. Ozcan, J. Ramirez, A. R. Gerson, K. S. Breuer, T. L. Hedrick. It pays to follow the leader: Metabolic cost of flight is lower for trailing birds in small groups [J]. PNAS, 2024, 121(26): e2319971121. https://doi.org/10.1073/pnas.2319971121

Proportional Control of Aerodynamic Forces using an Active Gurney Flap on a Wind Turbine Blade Section

Published in AIAA SCITECH 2023 Forum, 2023

Wind tunnel experiments over Re = 160,000–414,000 show that proportional deployment of an active Gurney flap improves lift and pitching moment with an increased lift-to-drag ratio, with the maximum effect near 70 degrees of deployment.

Recommended citation: S. Hao, A. Koh-Bell, R. Irani, J. Kirsch-Posner, K. Breuer. Proportional Control of Aerodynamic Forces using an Active Gurney Flap on a Wind Turbine Blade Section [C]. AIAA SCITECH 2023 Forum, AIAA 2023-0459. https://doi.org/10.2514/6.2023-0459