Abstract: A device in the form of a cap, for generating an isolation barrier for airborne pathogens between the wearer's face and the environment. A major part of the outer surface comprises filter material, allowing filtered air to flow from the environment into a chamber beneath the surface layer. A fan sucks air through the filter element and into the chamber. A horizontally oriented slot is situated across the visor portion of the cap structure, in front of the forehead of the person when the device is worn by the person. The slot has a width substantially smaller than the length. The flow of filtered air within the chamber is directed out of the slot as a curtain-like flow of filtered air in front of the face of the person. A cross-flow fan mounted just above the slot is most effective in generating the curtain flow.

Abstract: A device for use in extracting energy from an incoming fluid flow is presented.

Abstract: A control system is presented for controlling operation of a vertical axis wind turbine (VAWT) for generating energy from an incoming fluid flow. The control system comprises at least one flow affecting arrangement associated with at least one blade of the VAWT and a control unit connected to said flow affecting arrangement, the flow affecting arrangement comprising two flow affecting units located in two opposite sides of the blade respectively at a leading edge thereof, each flow affecting unit being operable for creating a blowing jet at the respective side of the blade thereby inducing an increase in a fluid flow momentum, the control unit being configured and operable for selectively activating the flow affecting units in alternating fashion according to a predetermined time pattern to oscillate the blowing jet at the opposite sides of the blade.

Abstract: The present invention relates to enhancing performance of fans and propellers using outsized Gurney flaps. Specifically, the current invention proposes the application of ‘outsized Gurney flaps’ (OGFs) to the trailing-edges of fan blades. According to an exemplary embodiment of the current invention, the Gurney flaps are larger than 10% of the fan blade chord length. Attaching OGFs is not only non-obvious; it seems counterintuitive, because it is akin to placing a large bluff body onto a flow. Preliminary experimental data acquired at Reynolds numbers typically exist during fan operation on idealized blade profiles showed a 100% increase in the generated lift and 40% to 60% increase in aerodynamic efficiency. This translates to significant improvements in fan performance at a given rpm, and/or significant saving in power and noise reduction for the same aerodynamic performance.

Abstract: The current invention provides significant performance improvements or significant energy savings for fans used in these applications: personal, industrial and automotive cooling, ventilation, vacuuming and dust removal, inflating, computer component cooling, propulsors for unmanned and manned air vehicles, propulsors for airboats, air-cushion vehicles, airships and model aircraft. Additionally, the invention provides higher performance such as higher lift and higher lift efficiency to small air vehicles. These advantages are achieved by using plasma actuators to provide active flow control effectors into thin fan blades and wing.

Abstract: A device for use in extracting energy from an incoming fluid flow is presented.

Abstract: A control system is presented for controlling operation of a vertical axis wind turbine (VAWT) for generating energy from an incoming fluid flow. The control system comprises at least one flow affecting arrangement associated with at least one blade of the VAWT and a control unit connected to said flow affecting arrangement, the flow affecting arrangement comprising two flow affecting units located in two opposite sides of the blade respectively at a leading edge thereof, each flow affecting unit being operable for creating a blowing jet at the respective side of the blade thereby inducing an increase in a fluid flow momentum, the control unit being configured and operable for selectively activating the flow affecting units in alternating fashion according to a predetermined time pattern to oscillate the blowing jet at the opposite sides of the blade.

Abstract: The present invention relates to enhancing performance of fans and propellers using outsized Gurney flaps. Specifically, the current invention proposes the application of ‘outsized Gurney flaps’ (OGFs) to the trailing-edges of fan blades. According to an exemplary embodiment of the current invention, the Gurney flaps are larger than 10% of the fan blade chord length. Attaching OGFs is not only non-obvious; it seems counterintuitive, because it is akin to placing a large bluff body onto a flow. Preliminary experimental data acquired at Reynolds numbers typically exist during fan operation on idealized blade profiles showed a 100% increase in the generated lift and 40% to 60% increase in aerodynamic efficiency. This translates to significant improvements in fan performance at a given rpm, and/or significant saving in power and noise reduction for the same aerodynamic performance.

Abstract: The current invention provides significant performance improvements or significant energy savings for fans used in these applications: personal, industrial and automotive cooling, ventilation, vacuuming and dust removal, inflating, computer component cooling, propulsors for unmanned and manned air vehicles, propulsors for airboats, air-cushion vehicles, airships and model aircraft. Additionally, the invention provides higher performance such as higher lift and higher lift efficiency to small air vehicles. These advantages are achieved by using plasma actuators to provide active flow control effectors into thin fan blades and wing.

Abstract: A method of controlling a shear layer for a fluid dynamic body introduces first periodic disturbances into the fluid medium at a first flow separation location. Simultaneously, second periodic disturbances are introduced into the fluid medium at a second flow separation location. A phase difference between the first and second periodic disturbances is adjusted to control flow separation of the shear layer as the fluid medium moves over the fluid dynamic body.

Abstract: To control vortices originating at the tips of a rotor's blades rotating through the air at a revolution frequency f, separation control device(s) are actuated to periodically introduce perturbations into the airflow moving over the blades. The periodic introduction of perturbations is controlled in accordance with a periodic modulating frequency of introduction f0 while the frequency of the perturbations so-introduced is designated as fe. Vortex control is achieved when the periodic modulating frequency of introduction f0 satisfies the relationship nf?f0?fe where n is the number of blades.

Abstract: A method and system for connecting a computer user with an information provider over a digitized speech connection. By determining what information a computer user is viewing, the system determines a telephone number associated with that information. The telephone number can be determined via (1) database lookup, (2) parsing of the information, and (3) a directory service using a portion of the name of the information as the query string. The telephone number can then be used to form a telephone connection with the information provider.

Abstract: To control vortices originating at the tips of a rotor's blades rotating through the air at a revolution frequency f, separation control device(s) are actuated to periodically introduce perturbations into the airflow moving over the blades. The periodic introduction of perturbations is controlled in accordance with a periodic modulating frequency of introduction f0 while the frequency of the perturbations so-introduced is designated as fe. Vortex control is achieved when the periodic modulating frequency of introduction f0 satisfies the relationship nf?f0?fe where n is the number of blades.

Abstract: A method of controlling a shear layer for a fluid dynamic body introduces first periodic disturbances into the fluid medium at a first flow separation location. Simultaneously, second periodic disturbances are introduced into the fluid medium at a second flow separation location. A phase difference between the first and second periodic disturbances is adjusted to control flow separation of the shear layer as the fluid medium moves over the fluid dynamic body.

Abstract: A method and device utilizes boundary layer separation control for the purpose of wake vortex alleviation. Trailing vortices are manipulated by varying the spanwise vortex-sheet strength via either passive or active boundary layer separation control. Boundary layer separation can be diminished or promoted to vary vortex properties, such as locations and strengths, so as to generate wake signatures that are unstable, resulting in complex three-dimensional interaction and rapid destruction of vortex coherence in the wake. Separation control can be achieved in either a time-dependent or a time-invariant mode.

Abstract: A vehicle capable of flight including at least one wing including at least one oscillatory momentum generator mounted therein. A thrust force from the oscillatory momentum generator is directed outwards over the wing causing a lift-generating air flow over a wing surface. A method of flying a vehicle including providing at least one wing having at least one oscillatory momentum generator mounted therein and applying a thrust force from the generator which is directed outwards over the wing and directed to the trailing edge so that a lift generating air flow is created.

Abstract: An aerial vehicle controlled and propelled by oscillatory momentum generators and method of flying a vehicle. A vehicle capable of flight is disclosed. The vehicle includes at least one wing including at least one oscillatory momentum generator mounted therein. A thrust force from the oscillatory momentum generator is directed outwards over the wing causing a lift-generating air flow over a surface of the at least one wing. Further disclosed is a method of flying a vehicle including providing at least one wing having at least one oscillatory momentum generator mounted therein and applying a thrust force from generator which is directed outwards over the wing so that a lift generating air flow is created.

Abstract: A method for inhibiting dynamic stall of an airfoil by causing a fluid to flow out of at least one location on the airfoil. This location may be anywhere on the airfoil; but if the location is within one-quarter of the airfoil chord from the leading edge and the fluid flow has non-zero net mass flux, then the fluid flow is modulated at a frequency described by a Strouhal ratio greater than one.