A fixed-wing aircraft that is capable of low airspeed, high angle of attack flight can serve an expanded range of mission goals. A typical propeller-driven small unmanned aircraft can be equipped with an engine that provides greater thrust than airplane weight; in post-stall states, the aircraft then depends on propeller backwash over the tail for control moment generation. Due to this dependen...

J. Deng, A. Stemmer, F. H. Miller, T. K. Rhee, R. Salem, D. Li, R. A. Omary, A. C. Larson Department of Radiology, Northwestern University, Chicago, IL, United States, Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States, Siemens Medical Solutions, Erlangen, Germany Introduction: Diffusion-weighted imaging (DWI) techniques use water mobility as an exogenous ...

An experimental study was performed to design and analyze a "pusher" propeller for use by a small, expendable, autonomous unmanned aerial vehicle (UAV) whose mission was to descend from 30,000 feet to sea level at an approximately constant descent rate over a 3-hour mission duration. The entire propeller design process, from airfoil selection to final part generation in the computer-aided draft...

This paper proposes a nonlinear dynamics model for a marine propeller able to reproduce the propeller thrust over the full four-quadrant range of propeller shaft speed and vessel speed. A two-state model has been identi…ed from experimental data. The model includes a state equation for the propeller shaft speed and one that describes the dynamics of the axial ‡ow velocity. The model reproduces ...

This paper discusses a study of the effects of pylon trailing edge blowing on pusher propeller performance and noise emissions. Experimental investigations were performed in a low speed open jet wind tunnel, using a powered propeller model and a generic pylon model. A novel pylon blowing system was integrated in the aft part of the pylon to provide a uniform outflow. The numerical analysis was ...

Surface-piercing propellers have been widely used in light and high-speed vessels because of their superior performance. One of the major steps in propeller selection algorithm is the determination of thrust as well as torque hydrodynamic coefficients. For the purpose of simplifying design and selection procedure, some relations are presented for determining hydrodynamic coefficients in some st...

A series of wind tunnel experiments was conducted to study the e ect of propeller solidity and thrust axis inclination on the propeller normalforce coe cient. Experiments were conducted in the Langley 14by 22-Foot Subsonic Tunnel with a sting-mounted, counterrotation, scalemodel propeller and nacelle. Con gurations had two rows of blades with combinations of 4 and 8 blades per hub. The solidity...

Positioning systems include different control functions for automatic positioning and guidance of marine vessels by means of proper action of the thruster and propeller devices. These may be controllable pitch propeller (CPP) with fixed speed, controllable speed with fixed pitch propeller (FPP), or controllable pitch and speed in combination. The positioning controller computes commanded forces...