Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 10 of 10 for “"propeller thrust"”.
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Measurements of Small-Scale Propellers Operating in the Vortex Ring State
The behavior of small-scale propellers operating in vertical descent and through the vortex ring state (VRS) was measured. In particular, a total of 26 propellers with varying diameters (9 to 11 in) were tested in the UIUC 2.8 x 4 ft wind tunnel at low Reynolds numbers to measure the propeller …
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Assessing Non-Planar Slicing and Carbon Fibre Filament Additives as Steps Towards 3D-Printed Drone Propellers
Propeller design dramatically influences the performance of a drone and its ability to complete a mission. Operators in the field cannot carry the best propeller for any possible conditions, but with the advent of capable end-user 3D printers, may be able to manufacture them. This research assesses …
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Torsional-axial coupling in the line shafting vibrations in merchant ocean going ships
… modes, i.e. torsional and axial, resulting from propeller action in the solid elastic shaft of the merchant ocean going ships is analyzed in this thesis. This type of vibration interaction can be described as torsionally-induced propeller thrust fluctuation. Generated longitudinal vibrations due …
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Perching with fixed wings
… of conventional autopilots. Given the tremendous thrust-to-weight ratio available on these small machines [1, 2], linear control approaches have recently produced impressive demonstrations that come close to matching this agility for a certain class of aerobatic maneuvers where the rotor or …
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Using H2 to supplement Diesel in Marine Applications
… A basic analysis of the brake efficiency, or propeller thrust efficiency, was carried out and it was found that the dual firing of the test engine with hydrogen and diesel achieved the best efficiencies at medium to high loads, which is the typical working range for these types of …
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Prediction of ship rudder-propeller interaction using parallel computations and wind tunnel measurements
… due to the interaction between a ship rudder and propeller. A parallel lifting suface panel program (PALISUPAN) has been written in Occam2 which is designed to run across variable sized square arrays of transputers. This program forms the basis of the theoretical method. The rudder and propeller …
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Propeller-Driven Rotor Twirl Phenomenon: Hover Performance, Dynamics, and Controls
Propeller-driven rotors use compact electric motors and propellers, mounted on the main rotor blade, to generate the mechanical torque needed to rotate the main rotor. The presented work details experiments and model developments in three major areas: hover performance, dynamics, and controls. The …
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A Low-Cost Unmanned Aerial Vehicle Research Platform: Development, Modeling and Advanced Control Implementation
… to obtain lookup tables relating airspeed to propeller thrust at constant throttle settings. Control systems are also designed for the regulation of this UAV along real-time trajectories. The reference trajectories are generated in real-time from a library of pre-specified motion primitives …
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The effect of turboprop propulsion on the aerodynamic benefits of formation flight
… generated by the use of an amalgamation of the propeller theory of Goldstein and Theodorsen. The downwash velocity field of a B747 during cruise, obtained via the use of the VFM Burnham-Hallock (VFM B-H) model programme, was verified against both the simulation conducted by Ehret and Oertel, in …
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Performance and slipstream characteristics of small-scale propellers at low Reynolds numbers
The low Reynolds number effects of small-scale propellers were investigated. At the Reynolds numbers of interest (below 100,000), a decrease in lift and an increase in drag is common making it difficult to predict propeller performance characteristics. A propeller testing apparatus was built to …