USA As Represented by Secretary of the Navy

Stephen A Huyer

David N Beal

James S Uhlman

John R Grant

Charles H Beauchamp

Stephen J Plunkett

Anuradha Annaswamy

Jeffrey S Marshall

Daniel L Macumber

Systems and methods for maneuvering an underwater vehicle by generating vehicle maneuvering forces from a propulsor of the vehicle are provided. A post-swirl propulsor is configured such that pitch angles of downstream stator blades can be individually varied. The variation in pitch results in the generation of multiple forces and moments for vehicle control.

Systems and methods to generate post-swirl propulsor side forces

Systems and methods for maneuvering an underwater vehicle by generating vehicle maneuvering forces from a propulsor of the vehicle are provided. A ducted, pre-swirl propulsor is configured such that the pitch angles of the stator blades of the upstream stator row can be varied. By varying the pitch angles of the stator blades about the circumference, a mean stator side force is generated. Subsequently, the axial velocity and swirl that is ingested into the inflow is varied. The rotor of the propulsor then generates a side force in response to the inflow.

Systems and methods to generate propulsor side forces

The invention as disclosed is an apparatus that controls the wake of stator blades on an underwater vehicle. The apparatus comprises one or more stator blades each with a movable trailing edge that when actuated in a controlled manner produces a periodic flapping motion upstream of a propulsion rotor. The controlled periodic flapping of the trailing edge the fills the stator blade wake enough to overcome the stator blade's own drag and fill its wake deficit. This has the effect of reducing the blade rate tonal noise of the propulsion rotor.

Apparatus for control of stator wakes

A dynamically reconfigurable wind turbine blade assembly includes a plurality of reconfigurable blades mounted on a hub, an actuator fixed to each of the blades and adapted to effect the reconfiguration thereof, and an actuator power regulator for regulating electrical power supplied to the actuators. A control computer accepts signals indicative of current wind conditions and blade configuration, and sends commands to the actuator power regulator. Sensors measure current wind conditions and current configurations and speed of the blades. An electrical generator supplies electrical power to the assembly. Data from the sensors is fed to the control computer which commands the actuator power regulator to energize the actuators to reconfigure the blades for optimum performance under current wind conditions.

Dynamically reconfigurable wind turbine blade assembly

A method for computing three dimensional unsteady flows about an object. An allowable error is established for the vorticity term calculations, and object geometry is provided giving surface points on an object and a region of interest. A mesh is established incorporating points on the object. Initial flow conditions are set at the surface. Vorticity values that will satisfy boundary conditions are set at the provided surface points. A new mesh is established incorporating the provided points and other points in the region of interest. Boxes are generated containing the provided points and other points. Velocities and pressures at each point are calculated from the flow conditions, vorticity values and boundary conditions., A time variable is incremented and each point is moved by applying the calculated velocity. Vorticity at each point is then recalculated. The method is iterated starting with the step of satisfying boundary conditions until the incremented time variable exceeds a predetermined value. satisfying boundary conditions until the incremented time variable exceeds a predetermined value.

Method for computing three dimensional unsteady flows by solution of the vorticity equation on a Lagrangian mesh

A method and apparatus for predicting flow over an object such as an air l or hydrofoil. The vortex strength for each of a plurality of vortex segments is obtained over an area of interest. The vortex segments are grouped into a series of square area defined by a series of boxes having different sizes. Initially a vortex strength is established for each of the smallest boxes and the coefficients then provide characteristic vortex strengths for a given box. The conversion of these vortex strengths into velocities is accomplished by directly computing the velocity of a given vorticity segment as influenced by all the vorticity segments in the box containing the given vorticity segment and the direct influence of each vortex segment in that box and any neighboring boxes. The influence of other vorticity segments outside the neighboring boxes is provided by using the influence of the average vortex strength of a given box or group of boxes. This approach significantly reduces the number of computations required to obtain the prediction.

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Saunderstown, RI, United States of America

Stephen A Huyer