Theses and Dissertations from UMD

Permanent URI for this communityhttp://hdl.handle.net/1903/2

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

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    Development and Investigation of a Flapping Rotor for Micro Air Vehicles
    (2007-07-09) Fitchett, Brandon Kurt; Chopra, Inderjit; Aerospace Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    This thesis describes the concept, design and testing of a micro air vehicle rotor testbed capable of independently controlled blade rotation and powered blade flapping. The design, dubbed the "Flotor", combined the benefits of a conventional MAV helicopter rotor with avian based flapping motion. The Flotor was tested as a conventional rotor, a conventional rotor with powered blade flapping, and a torqueless, freely rotating rotor with powered blade flapping. As a conventional rotor with a maximum figure of merit of 0.5, the results from the Flotor were similar to previously published experiments. With conventional rotation plus powered blade flapping at up to 8 per rotor revolution at a reduced frequency of 0.6, the maximum thrust increased by up to 15% due to delayed stall. The torque required at moderate thrust levels was reduced by up to 30%. The results from a 2-D quasi-steady blade element momentum analysis predicted average rotor loads accurately below 20° collective. As the first attempt at a torqueless flapping MAV rotor, the Flotor was capable of producing thrust and blade loadings comparable to flying animals, but less than current MAVs.