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A Study Of The Aeroacoustics Of Swept Propellers For Small Unmanned Aerial Vehicles, Arthur David Wiedemann

Mechanical & Aerospace Engineering Theses & Dissertations

In recent years, small unmanned aerial vehicles (UAVs) have increased in availability and use in both public and commercial sectors. This increased use of small UAVs or “drones” has the unfortunate consequence of introducing excessive noise into communities where they operate. Implementation of noise reduction methods is necessary if we wish to see expanded use of drones in public areas. With electric propulsion, the primary source of noise is the rotor/propeller used in contemporary multi-rotor configurations. In this thesis, the aerodynamics and acoustic behavior of various swept propellers is examined with computational and experimental methods.

A family of propeller geometries …

Characterization And Optimization Of A Propeller Test Stand, Colin Bruce Leighton Benjamin

Mechanical & Aerospace Engineering Theses & Dissertations

In recent history, there has been a rapid rise in the use of drones, and they are expanding in popularity each year. The widespread use and future capabilities of these unmanned aerial vehicles (UAVs) will call for increased study and classification of propellers to maximize their performance. As a result, it is necessary to have continuity in the development, maximization, and optimization of propeller test stand’s capability to collect accurate and precise measurements. It is of significant advantage to have the capability of accurately characterizing a propeller based on its thrust and torque. In this study, a propeller test stand …

Development And Implementation Of A Propeller Test Capability For Gl-10 "Greased Lightning" Propeller Design, Brian Edward Duvall

Mechanical & Aerospace Engineering Theses & Dissertations

Interest in small unmanned aerial vehicles has increased dramatically in recent years. Hybrid vehicles which allow forward flight as a fixed wing aircraft and a true vertical landing capability have always had applications. Management of the available energy and noise associated with electric propeller propulsion systems presents many challenges. NASA Langley has developed the Greased Lightning 10 (GL-10) vertical takeoff, unmanned aerial vehicle with ten individual motors and propellers. All are used for propulsion during takeoff and contribute to acoustic noise pollution which is an identified nuisance to the surrounding users. A propeller test capability was developed to gain an …

Studies On The Interference Of Wings And Propeller Slipstreams, Ramadas K. Prabhu

Mechanical & Aerospace Engineering Theses & Dissertations

The small disturbance potential flow theory is applied to determine the lift of an airfoil in a nonuniform parallel stream. The given stream is replaced by an equivalent stream with a certain number of velocity discontinuities, and the influence of these discontinuities is obtained by the method of images. Next, this method is extended to the problem of an airfoil in a nonuniform stream of smooth velocity profile. This model allows perturbation velocity potential in a rotational undisturbed stream. A comparison of these results with numerical solutions of Euler equations indicates that, although approximate, the present method provides useful information …