USA As Represented by Secretary of the Navy

James S Uhlman

William P Krol

Stephen A Huyer

John R Grant

Chahee P Cho

Ivan N Kirschner

Ralph A Bedingfield

Abraham N Varghese

Jeffrey S Marshall

A system and method of use are provided for introducing tangential control fluid flows along the surface of an aerodynamic member. The fluid flows are directed toward a coanda surface disposed at the trailing edge of the aerodynamic member. At least two injection slots are provided on opposite sides of the aerodynamic member to produce opposing forces. Control of the flow of fluid from each slot determines the net effect of these opposing forces. Smart material actuators are used to control the flow of fluid from each slot by varying the size of each slot.

Adaptive material actuators for Coanda effect circulation control slots

A stabilizing device for a supercavitating vehicle that isolates re-entrant jet flows of liquid from its cavity. The device has a receiving means positioned on the supercavitating vehicle where the re-entrant jet flow impinges on the supercavitating vehicle. An exit means is joined to the receiving means for carrying the received re-entrant jet flow out of interference with the cavity. The exit means includes an exhaust nozzle joined to the aft of the supercavitating vehicle and a re-entrant jet nozzle positioned in communication between the receiving means and said exhaust nozzle transferring said received re-entrant jet flow into the exhaust nozzle. This stabilizes the cavity and improves controllability and maneuverability of the supercavitating vehicles while also reducing the gas ventilation required to maintain the cavity. Furthermore, this reduces self-generated noise allowing improved operation of acoustical sensors incorporated in the vehicle.

Device for stabilizing re-entrant cavity flows past high-speed underwater vehicles

A method for calculating parameters about an axisymmetric body in a cavity is provided. The user provides data describing the body, a cavity estimate, and convergence tolerances. Boundary element panels are distributed along the body and the estimated cavity. Matrices are initialized for each panel using disturbance potentials and boundary values. Disturbance potential matrices are formulated for each panel using disturbance potential equations and boundary conditions. The initialized matrices and the formulated matrices are solved for each boundary panel to obtain panel sources, dipoles and cavitation numbers. Forces and velocities are computed giving velocity and drag components. The cavity shape is updated by moving each panel in accordance with the calculated values. The method then tests for convergence against a tolerance, and iterates until convergence is achieved. Upon completion, parameters of interest and the cavity shape are provided. This invention also allows determiniation of cavity shape for a cavitation number.

Non-linear axisymmetric potential flow boundary model for partially cavitating high speed bodies

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 combination motor and pump assembly comprising a housing, a shaft rotaty mounted in the housing, and an impeller fixed to the shaft in the housing, said impeller comprising alternately magnetically polarized portions. The assembly further comprises stator means fixed in the housing adjacent the impeller, the stator means comprising an array of pole pieces and windings associated therewith for receiving electrical alternating current. Fluid inlet means and outlet means are provided in the housing in communication with the impeller. The impeller reacts to current received by the stator means as a motor rotor and rotates in response to excitation of the pole pieces by the current. The rotation of the rotor serves to move fluid in the housing from the inlet to the outlet means.

Combination motor and pump assembly

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.

Growing community of inventors

Newport, RI, United States of America

James S Uhlman