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1. Load reduction on a clipper liberty wind turbine with linear parameter-varying individual blade pitch control: Load reduction on a clipper liberty wind turbine with linear parameter-varying individual blade pitch control

   https://doi.org/10.1002/we.2121  

   Ossmann, Daniel ; Theis, Julian ; Seiler, Peter ( October 2017 , Wind Energy)
2. A theory of pitch for the hydrodynamic properties of molecules, helices, and achiral swimmers at low Reynolds number

   https://doi.org/10.1063/5.0152546  

   Duraes, Anderson D. ; Gezelter, J. Daniel ( October 2023 , The Journal of Chemical Physics)

   We present a theory for pitch, a matrix property that is linked to the coupling of rotational and translational motion of rigid bodies at low Reynolds numbers. The pitch matrix is a geometric property of objects in contact with a surrounding fluid, and it can be decomposed into three principal axes of pitch and their associated moments of pitch. The moments of pitch predict the translational motion in a direction parallel to each pitch axis when the object is rotated around that axis and can be used to explain translational drift, particularly for rotating helices. We also provide a symmetrized boundary element model for blocks of the resistance tensor, allowing calculation of the pitch matrix for arbitrary rigid bodies. We analyze a range of chiral objects, including chiral molecules and helices. Chiral objects with a Cn symmetry axis with n > 2 show additional symmetries in their pitch matrices. We also show that some achiral objects have non-vanishing pitch matrices, and we use this result to explain recent observations of achiral microswimmers. We also discuss the small but non-zero pitch of Lord Kelvin’s isotropic helicoid.

    

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3. Experimental mitigation of large-amplitude transverse gusts via closed-loop pitch control

   https://doi.org/10.1103/PhysRevFluids.8.064701  

   Sedky, Girguis ; Gementzopoulos, Antonios ; Lagor, Francis D. ; Jones, Anya R. ( June 2023 , Physical Review Fluids)
4. Altitude Control of a Tethered Multi-Rotor Autogyro in 2-D Using Pitch Actuation via Differential Rotor Braking

   https://doi.org/10.23919/ACC55779.2023.10155811  

   Noboni, Tasnia ; McConnell, Jonathan ; Das, Tuhin ( May 2023 , Proceedings of the American Control Conference)
5. Effects of wing pitch kinematics on both aerodynamic and olfactory functions in an upwind surge

   https://doi.org/10.1177/0954406220907950  

   Li, Chengyu ( January 2021 , Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science)

   Flapping wings of insects serve for both generating aerodynamic forces and enhancing olfactory sensitivities when navigating on the odor-rich planet. Despite the extensive investigations of the aerodynamic function of flapping wings, we have limited understanding of how the flapping wings potentially affect the physiological sensitivities during flight. In this paper, direct numerical simulations were used to investigate a fruit fly model in an upwind surging motion. The wing pitch kinematics were prescribed using a hyperbolic function, which can change the wing pitch profile from a sinusoidal function to a step function by adjusting the “C” factor in the hyperbolic function. Both aerodynamic performance and olfactory detections were quantified at various wing pitch kinematics patterns. The effects of flapping wings on the odor transport were visualized using the Lagrangian approach by uniformly releasing passive odor tracers in upstream. The study revealed that the insect had the potential to achieve higher aerodynamic performance by tailoring wing pitch kinematics, but it could reduce the odor mass flux around the antenna. It was suspected that the natural flyers might sacrifice certain aerodynamic potential to enhance their olfactory sensitivity for surviving purposes. In addition, a trap-and-flick mechanism is proposed here during the supination phase in order to enhance the olfactory sensitivity. Similar to the clip-and-fling mechanism for enhancing the force generation during the pronation phase, the newly proposed trap-and-flick mechanism is also due to the wing-wing interaction in flapping flight. These findings could provide important implications for engineering applications of odor-guided flapping flight.

    

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