Abstract: A drill bit for chiselling rock includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has a cutting edge, an intake opening, and an intake passage and where the intake passage connects the intake opening to the delivery passage. A first portion of the intake passage which adjoins the intake opening has a first inclination with respect to a drill bit axis, a second portion of the intake passage which adjoins the hollow shank has a second inclination with respect to the drill bit axis, and the second inclination is greater than the first inclination.

Abstract: A fluidic circuit configured to spray an oscillating pattern of fluid droplets, having an inlet in fluid communication with a source and including a power nozzle with an oscillation chamber having a fluid jet steering section in fluid communication with the power nozzle and having either (a) a first fluid pressure accumulating volume opposite a second fluid pressure accumulating volume or (b) a first fluid jet attachment feature opposing a second fluid jet attachment feature. The fluid jet steering section is in fluid communication with and emits a fluid jet into an oscillation inducing interaction region with opposing first and second side wall ears or features which define an oscillation inducing interaction region in the oscillation chamber for causing the jet of fluid to rhythmically sweep back and forth between the sidewalls in the oscillation chamber and create a distally projecting oscillating spray.

Abstract: Check valve units having one or more sound attenuating members are disclosed. A check valve unit includes a housing defining an inlet port, an outlet port, and a chamber in fluid communication therewith thereby defining a flow path from the inlet port through the chamber to the outlet port. The chamber includes first and second valve seats and has a sealing member disposed therein that is moveable from a position seated on the first valve seat to a position seated on the second valve seat. A sound attenuating member is disposed in the flow path downstream of the chamber, within the chamber, or both. In another embodiment, the check valve unit includes a Venturi portion in fluid communication with the chamber. The Venturi portion has a fluid junction with the flow path downstream of the chamber or forms the discharge section of the Venturi portion thereby defining the outlet port.

Abstract: A hydraulic damping apparatus comprising a conduit for a hydraulic fluid having a port in a wall of the conduit; a resonator having a chamber and a neck, the neck being arranged to provide fluid communication between the chamber and the port. The apparatus further comprises a first pressure sensor arranged to sense pressure in the conduit upstream of the port, a second pressure sensor arranged to sense pressure in the conduit downstream of the port, and a controller configured to determine the amplitude of a pressure fluctuation sensed by the first pressure sensor and the amplitude of a pressure fluctuation sensed by the second pressure sensor. The controller is further configured to vary a resonant frequency of the resonator in accordance with a difference between the amplitude of the pressure fluctuation sensed by the first pressure sensor and the amplitude of the pressure fluctuation sensed by the second pressure sensor.

Abstract: A device for displacing a small volume of liquid under the effect of an electric control, including a first substrate with a hydrophobic surface provided with a first electrical conductor, a second electrical conductor positioned facing the first conductor, and a third conductor, forming with the second conductor, a mechanism for analyzing or heating a volume of liquid.

Abstract: The invention provides methods for assessing one or more predetermined characteristics or properties of a microfluidic droplet within a microfluidic channel, and regulating one or more fluid flow rates within that channel to selectively alter the predetermined microdroplet characteristic or property using a feedback control.

Abstract: A fluidic system is disclosed. The system comprises a plurality of fluidic oscillatory actuators, and at least one synchronization conduit connecting two or more of the actuators such as to effect synchronization between oscillations in the two or more connected actuators.

Abstract: The invention provides methods for assessing one or more predetermined characteristics or properties of a microfluidic droplet within a microfluidic channel, and regulating one or more fluid flow rates within that channel to selectively alter the predetermined microdroplet characteristic or property using a feedback control.

Abstract: A metabolite monitoring system comprising a microdialysis probe including a semi-permeable membrane and a probe flow path passing from an inlet through a sensing volume adjacent to said semi-permeable membrane to an outlet, a fluid delivery device for delivering dialysate to said inlet; and a metabolite monitoring system associated with said outlet for monitoring a concentration of at least one metabolite in said dialysate from said microdialysis probe, wherein said fluid delivery device is configured to deliver a pulsed flow of said dialysate to said inlet.

Abstract: An apparatus for generating high-speed pulsed fluid jets. A valve assembly has a valve body with an inlet and an outlet. A valve shuttle is slidably or movably mounted with respect to the valve body. The valve shuttle is positioned within a cavity of the valve body and divides the cavity into an upper or inlet cavity and a lower or outlet cavity. The valve shuttle has a passage in communication with the upper cavity and the lower cavity. In an open condition of the valve assembly, fluid communication is formed between the inlet, the inlet cavity, the passage, the outlet cavity and the outlet.

Abstract: An arrangement for the exposure of a pumpable medium to an electric field. The arrangement comprises, at least two power supplies (100) for the generation of electrical voltage, at least one non-conducting chamber (102) for pumping said pumpable medium, which said at least one chamber (102) is provided with a first (106) and a second electrode plate (108), a control means (104) for controlling said at least two power supplies (100). During control the control means (104), by synchronous control, establishes a series connection between at least two of said at least two power supplies (100), the first electrode plate (106) and the second electrode plate (108). A resulting composite voltage arises between the first (106) and the second electrode plate (108), which resulting composite voltage will result in an electric field between the first (106) and the second electrode plate (108). The pumpable medium is exposed to the electric field.

Abstract: An airflow control device 10 in an embodiment includes: a vortex shedding structure portion 20 discharging an airflow flowing on a surface in a flow direction as a vortex flow; and a first electrode 40 and a second electrode 41 disposed on a downstream side of the vortex shedding structure portion 20 via a dielectric. By applying a voltage between the first electrode 40 and the second electrode 41, flow of the airflow on the downstream side of the vortex shedding structure portion 20 is controlled.

Abstract: A method of manufacturing a fluidic oscillator insert for use in a subterranean well can include forming the insert with a conical housing engagement surface thereon, and forming at least one fluidic oscillator on a substantially planar surface of the insert. A well tool can include a housing assembly, at least one insert received in the housing assembly, the insert having a fluidic oscillator formed on a first surface thereof, the insert being at least partially secured in the housing assembly by engagement of conical second and third surfaces formed on the insert and housing assembly, and a cover which closes off the first surface on the insert. An insert for use in a well tool can include a conical housing engagement surface, and at least one fluidic oscillator formed on a substantially planar surface. The fluidic oscillator produces oscillations in response to fluid flow through the fluidic oscillator.

Abstract: A fluidic oscillator can include an input, first and second outputs on opposite sides of a longitudinal axis of the oscillator, whereby a majority of fluid which flows through the oscillator exits the oscillator alternately via the first and second outputs, first and second paths from the input to the respective first and second outputs, and wherein the first and second paths cross each other between the input and the respective first and second outputs. Another oscillator can include an input, first and second outputs, whereby a majority of fluid flowing through the fluidic oscillator exits the oscillator alternately via the first and second outputs, first and second paths from the input to the respective first and second outputs, and a feedback path which intersects the first path, whereby reduced pressure in the feedback path influences the majority of fluid to flow via the second path.

Abstract: This supersonic pulse flow device is intended to provide a technical solution in a number of fields where the injection of a flow must be pulsed as required by the process or in order to limit the power consumption and size of the pumping means. In the case of flows achieved by means of a Laval nozzle, it is possible to generate a uniform supersonic jet at very low temperature (currently up to 20 K), which is stable over hydrodynamic periods of time between 150 and 1000 microseconds. This device is aimed as solving problems relating to the use of aerodynamic tools in research and development and in industrial processes.

Abstract: An ultrasonic mixing system having a treatment chamber in which at least two separate phases can be mixed to prepare an emulsion is disclosed. Specifically, at least one phase is a dispersed phase and one phase in a continuous phase. The treatment chamber has an elongate housing through which the phases flow longitudinally from a first inlet port and a second inlet port, respectively, to an outlet port thereof. An elongate ultrasonic waveguide assembly extends within the housing and is operable at a predetermined ultrasonic frequency to ultrasonically energize the phases within the housing. An elongate ultrasonic horn of the waveguide assembly is disposed at least in part intermediate the inlet and outlet ports, and has a plurality of discrete agitating members in contact with and extending transversely outward from the horn intermediate the inlet and outlet ports in longitudinally spaced relationship with each other.

Abstract: A high flow volume nasal irrigation device for alternating pulsatile and continuous fluid flow includes a segmented dip tube with a free end extending inside a squeeze bottle configured to convey a liquid under an elevated chamber pressure from a reservoir therein to a lower pressure outside the bottle. The device also includes an elastic segment at the free end of the tube configured to oscillate about a bending in the segment in response to a differential pressure between an internal pressure and the chamber pressure, the segment having an elastic restoring force in opposition to the bending. The disclosed device further includes a pulsatile portion of the elastic segment configured to close at the segment bending and to reopen under the elastic restoring force and to thus generate a periodic pulsatile fluid flow through the tube with a period corresponding to the elastic segment oscillation.

Abstract: A device for vibrating tubing as it is inserted into a wellbore is disclosed. The device has a fluidic switch that has no moving parts. The fluidic switch is connected to a piston that oscillates back and forth in a cylinder. The piston is the only moving part. As the piston oscillates, it blocks and unblocks openings in the cylinder or other components. The movement of the piston controls the timing of the oscillation, and also generates an impulse or vibration. The vibration may reduce the friction between the tubing and the wellbore.

Abstract: A liquid control apparatus is used for controlling the movement of liquid in a microfluidic device having a flow channel for holding liquid. The apparatus comprises a vibration wave generating section for generating a vibration wave to be applied to the microfluidic device and a signal supplying section for supplying drive signals to the vibration wave generating section so as to oscillate in an oscillation mode selected from a transfer mode for moving liquid in a predetermined direction, a stop mode for stopping the movement of liquid, a mixing and/or agitation mode for mixing and/or agitating liquid and a localization mode for localizing a predetermined substance in liquid.

Abstract: A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either electric current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to electrokinetically inducing fluid flow to confine a selected material in a region of a microchannel that is not influenced by an electric field. Other structures for inducing fluid flow in accordance with this invention include nanochannel bridging membranes and alternating current fluid pumping devices. Applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

Abstract: A fuel injection system includes a fuel injector that includes a nozzle assembly and at least one passageway that includes at least one fluid oscillator. The at least one passageway extends from a nozzle orifice, positioned on the outside of the fuel injector, to inside the fuel injector. Fuel from inside the fuel injector moves through the at least one fluid oscillator and oscillates between a high injection rate and a low injection rate as it moves through the at least one nozzle orifice and into the combustion chamber.

Abstract: A device includes a fluid flow channel having a channel inlet for receiving a pressurized fluid for flow through the fluid flow channel and a channel outlet for discharging the pressurized fluid therefrom. A passive flow element is situated within the fluid flow channel or proximate to the channel inlet. The passive flow element includes an element inlet for receiving the pressurized fluid, and an element outlet. The passive flow element also includes a cavity for receiving the pressurized fluid from the element inlet and generating a periodic flow variation of the pressurized fluid so as to modulate the pressurized fluid flow rate through the element outlet.

Abstract: A fluidic oscillator suitable for use at colder temperatures for utilizing a pressurized liquid to generate a uniform spatial distribution of droplets has (a) an inlet for the pressurized liquid, (b) a set of three power nozzles that are fed by the pressurized liquid, (c) an interaction chamber attached to the nozzles and which receives the flow from the nozzles, wherein this chamber has an upstream and a downstream portion, with the upstream portion having a pair of boundary edges and a longitudinal centerline that is approximately equally spaced between the edges, and wherein one of the power nozzles is directed along the chamber's longitudinal centerline, (d) a throat from which the liquid exhausts from the interaction chamber, and (e) an island located in the interaction chamber, with this island being situated downstream of the power nozzle that is directed along the chamber's longitudinal centerline.

Abstract: An ultrasonic mixing system having a treatment chamber in which at least two separate phases can be mixed to prepare an emulsion is disclosed. Specifically, at least one phase is a dispersed phase and one phase in a continuous phase. The treatment chamber has an elongate housing through which the phases flow longitudinally from a first inlet port and a second inlet port, respectively, to an outlet port thereof. An elongate ultrasonic waveguide assembly extends within the housing and is operable at a predetermined ultrasonic frequency to ultrasonically energize the phases within the housing. An elongate ultrasonic horn of the waveguide assembly is disposed at least in part intermediate the inlet and outlet ports, and has a plurality of discrete agitating members in contact with and extending transversely outward from the horn intermediate the inlet and outlet ports in longitudinally spaced relationship with each other.

Abstract: An improved fluidic insert, that operates on a pressurized liquid flowing through the insert to generate a jet of liquid that flows from said insert and into the surrounding gaseous environment to form a spray of liquid droplets, includes: (a) a member having top, front and rear outer surfaces, (b) a fluidic circuit located within this top surface and having an inlet, an outlet and a channel whose floor and sidewalls connect the inlet and outlet, and a barrier located proximate the outlet that rises from the channel floor and is configured such that: (i) it divides the channel in the region of the barrier into what are herein denoted as two power nozzles, and (ii) each of these nozzles has a downstream portion that is configured so as to cause the liquid flowing from the nozzles to generate flow vortices behind the barrier that are swept out of the outlet in such a manner as to control the lateral rate of spread of liquid droplets from the insert.

Abstract: For achieving a fluidic device, being able to be made small in sizes, comprising a fluid inflow opening 1, a connector duct 2, and a fluid jet nozzle, wherein the connector duct 2 is constructed with curves, and is further constructed with two (2) pieces of flow passages, being symmetric on both sides. Constructing the connector duct with the curves reduces resistance of fluid within the duct, and further dividing the connector duct into two (2) parts in both side enhances the flows at confluent point in the duct (increase of the flow velocity).

Abstract: A fluidic oscillator suitable for use at colder temperatures for generating an exhaust flow in the form of an oscillating spray of fluid droplets has an inlet for pressurized fluid, a pair of power nozzles configured to accelerate the movement of the pressurized fluid, a fluid pathway that connects and allows for the flow of pressurized fluid between its inlet and the power nozzles, an interaction chamber which is attached to the nozzles and receives the flow from the nozzles, a fluid outlet from which the spray exhausts from the interaction chamber, and, at each power nozzle, a step in the height elevation of the floor of the power nozzle with respect to that of the interaction chamber for increasing the instability of the flow from the power nozzles.

Abstract: A microreactor containing a plurality of introduction channels 21 and 22 for introducing a plurality of liquids, a merging section 23 for merging the plurality of introduction channels 21 and 22, and a reaction channel 41 located on a downstream side of the merging section 23, characterized in that a flow control section 80 is located on a downstream side of the merging section 23 and an upstream side of the reaction channel 41, and the flow control section 80 contains in a channel 81 thereof a movable particle 82. According to the constitution, such a microreactor can be provided that the flow state in the reaction channel 41 is controlled to realize a flow state with good reproducibility.

Abstract: A fluidic oscillator suitable for use at colder temperatures for generating an exhaust flow in the form of an oscillating spray of fluid droplets has an inlet for pressurized fluid, a pair of power nozzles configured to accelerate the movement of the pressurized fluid, a fluid pathway that connects and allows for the flow of pressurized fluid between its inlet and the power nozzles, an interaction chamber which is attached to the nozzles and receives the flow from the nozzles, a fluid outlet from which the spray exhausts from the interaction chamber, and a means for increasing the instability of the flow from the power nozzles, with this means being situated in a location chosen from the group consisting of a location within the fluid pathway or proximate the power nozzles. In a first preferred embodiment, the flow instability generating means comprises a protrusion that extends inward from each side of the fluid pathway so as to cause a flow separation region downstream of the protrusions.

Abstract: A system for control of a fluid flow. The system includes an array of fluidic oscillators. Each fluidic oscillator carries an oscillating flow of the fluid and includes a throat, an input port connected to the throat, two control ports connected to the throat and two output ports extending from the throat. A feedback line is connected to each of the two output ports and each of the two control ports. The system further includes a plenum connected to the input ports of the fluidic oscillators to supply the fluid to the fluidic oscillators and a feedback chamber disposed along each feedback line of each fluidic oscillator to provide a feedback path for the control fluid to cause oscillatory fluid motion between the first output port and the second output port, the frequency of which may be modulated by adjusting the volume of the feedback chamber.

Abstract: A fluidic pulse generator system includes two fluidic diverter valves that are both controlled by a single fluidic pilot valve. The fluidic pilot valve and the two fluidic diverter valves are each adapted to receive a flow of pressurized fluid. The flow of pressurized fluid through the fluidic pilot valve is controlled in response to pressurized fluid flow through a control valve. In turn, the flow of pressurized fluid through the two fluidic diverters valves is simultaneously controlled in response to the flow of pressurized fluid through the fluidic pilot valve.

Abstract: A fluid amplifier is presented. The fluid amplifier comprises at least one control valve for controlling at least one of a first control fluid flow and a second control fluid flow. That is, the control valve has a movable element for selectively opening and closing at least one of the first control stream channel and the second control fluid flow channel. The control valve also includes a diaphragm for isolating the moveable element.

Abstract: Systems and methods for metering microfluidic volumes are provided. A discrete plug may be separated from a larger volume of first fluid by injecting a second fluid, such as a gas, into a channel containing the first fluid. The injection of the second fluid to isolate the desired amount of the first fluid may be controlled through timing of flows, visual indicators and/or automated control systems using optical or electrical sensors.

Abstract: A method and mechanism of producing a suction and periodic excitation flow. The method includes providing fluid flow from jet port with diameter dl at a controlled input pressure (Pin), directing the flow to a conduit with diameter d2, >d1, allowing additional fluid to join the flow through suction slot(s) to create an amplified flow in the conduit, further directing the amplified flow in a first direction by applying a transverse pressure differential, further redirecting the amplified flow in another direction by modifying an angle by which the transverse pressure differential is applied and iteratively repeating the further directing and further redirecting so that the amplified flow oscillates between the directions. The suction and periodic excitation flows may be employed, for example, to effectively control boundary layer separation. A mechanism for automated performance of the method is also disclosed.

Abstract: In a hot water distribution system, the water oscillation in hot water supply line maintains hot water line in heated condition by ensuring heat transfer from the water heater to a hot water line executing regenerative heat transfer technique. Fulfillment of longitude water oscillations is ensured by installation of at least two flexible elements such as pressure air accumulators, wherein one is connected to water heater reservoir, and another is connected to hot water line in vicinity to most remote hot water fixture. This can be combined with one of pressure air accumulators initiator of water oscillations that is used for initiation and maintaining of the water oscillation. Heat spreads through the hot water line ensuring hot state of water near all fixtures of the line ensuring instantaneous hot water supply at moment of tap opening.

Abstract: Methods and apparatus for reducing drag in fluid flow through pipes that utilizes microbubbles and acoustic energy are provided. A gas ejector for microbubble generation in a pipe is provided and includes a pipe comprising a wall having inner and outer diameters and at lease one orifice in the wall for ejecting gas microbubbles into the pipe. To cause the formation of the microbubbles, a flow restrictor is provided in the pipe, with the flow restrictor being spaced from the inner diameter of the pipe wall and positioned adjacent the at least one orifice. The flow restrictor causes and increase in the velocity of the fluid in the pipe past the at least one orifice, and produces a pressure drop which draws gas into the orifice. That gas is then ejected into the pipe in the form of microbubbles. Acoustic energy may be used to provide further reductions in drag.

Abstract: A fluidic oscillator is disclosed, wherein the fluidic oscillator includes a fluid source and a housing coupled to the fluid source. At least one recess is formed within the housing. An insert resides within each at least one recess; the insert provides at least one substantially flat surface. A fluid flowpath in the at least one substantially flat surface generates fluid pulses from fluid received from the fluid source.

Abstract: Methods of molding fluidic oscillator device having at least a power nozzle for projecting a jet of liquid into an interaction region with an upstream end, opposing side walls, opposing top and bottom walls, and a pair of control ports at the upstream end. The side walls diverge from the power nozzle. A mold cavity is provided in which the power nozzle, interaction region (IR) and control ports can be molded as a core without any seam lines. For a crossover type IR in which the upstream ends diverge and the downstream ends converge to a common throat area and coupled to an outlet aperture, a further mold cavity is provided in which the converging portion of the crossover type interaction region is formed as a second core having a joinder line to the first the core which is transverse to the direction of liquid flow in the fluidic.

Abstract: A method of mixing two or more fluids comprising pulsing the flow of two fluids selected from the two or more fluids, reversing the flow of one of the pulsed fluid, bringing into contact the fluids and causing them to mix. A device for mixing the fluids is also provided.

Abstract: A fluidic oscillator capable of generating free fluid jets having distinctive, controllable and industrially/commercially useful flow patterns has a switching chamber having an inlet port that allows a pressurized fluid to enter and flow through the oscillator, an exhaust passage having a sidewall that forms one boundary wall of the switching chamber, a container passage having a sidewall that forms the second boundary wall of the switching chamber, a compliance member connected to the distal end of the container passage, and an expansion chamber connected to the distal end of the exhaust passage, with the expansion chamber having an exhaust orifice that allows fluid to flow from the oscillator. In operation, such an oscillator yields a contained fluid jet that issues from the inlet port into the swishing chamber and alternately switches its flow direction between the container and exhaust passages.

Abstract: Fluid and fuel delivery systems reducing pressure fluctuations and engines including such systems are disclosed. Such systems use a conduit that attenuates pressure fluctuations. Preferably, the conduit attenuates pressure fluctuations by reflecting a portion of a pressure wave within the fluid flow so that reflected pressure waves within the flow interfere with incident pressure waves within the flow, thereby reducing the pressure fluctuations in one embodiment, such a conduit may be formed as a quarter wave stub, in line with the fluid flow. Advantageously, exemplary of the invention, hoot noise in an engine may be reduced by damping pressure fluctuations in the fuel delivery system to the engine.

Abstract: A micro-electromechanical system and method for continuous laminar fluid mixing. An embodiment of the invention described in the specification includes a mixing channel, a first delivery channel that is connected to the mixing channel, and a second delivery channel that is connected to the mixing channel. A first pump mechanism produces pulses in the first delivery channel. A second pump mechanism produces pulses in the second delivery channel. The first pulsed fluid stream and the second pulsed fluid stream merge in the mixing channel to form a mixed fluid. The pulses in the fluids operate to distort the interface between the fluids to facilitate diffusion between the fluids.

Abstract: A fluidic nozzle having multiple operating modes comprising a fluidic oscillator circuit having an oscillation chamber having an upstream end and a downstream end and a power nozzle at the upstream end for introducing a jet of a liquid (water) into the oscillation chamber. An outlet throat at the downstream end has a width, which does not allow the oscillation circuit to fill up and start to oscillate without entrained liquid. A pair of control ports are at the upstream end of the oscillation chamber and a pair of feedback passages connect said control ports to downstream ends of said oscillation chamber adjacent said outlet throat. A pair of controllable entrainment holes are provided in the oscillation chamber at the upstream end and a valve opens and closes the entrainment holes, such that when the entrainment holes are open to air, air is entrained and the oscillator does not oscillate.

Abstract: A method and apparatus for ejecting a second fluid into the near-wall region of the boundary layer of a first fluid, so that the second fluid hugs the wall. This alone reduces drag by modifying the behavior of the near-wall structure, thereby reducing the frequency of burst and sweep cycles, even when the first and second fluids are identical. Further, one or more additives, such as polymer, surfactant, micro-bubbles, a combination thereof, and/or using a second fluid having an elevated temperature as compared to the temperature of the first fluid, may be used to achieve much greater drag reduction as well as lower dissipation rates than previously possible. The second fluid is ejected using a convex Coanda surface (7) and at a controlled velocity that is a small fraction of the velocity of the first fluid moving along the wall so that the flow lines of the second fluid are substantially aligned with the flow lines of the first fluid.

Abstract: The invention provides a fluidic oscillator that is symmetrical about a longitudinal plane of symmetry (P), comprising an enclosure defining an oscillation chamber and having an inlet opening and an outlet opening through which the fluid flows and which are in alignment in said plane (P) in a “longitudinal” first direction (A), said inlet opening being made in the form of a slot that is narrow in a second direction (B) extending transversely to said plane (P) and elongate in a third direction (C) parallel to said plane (P) and perpendicular to said longitudinal first direction (A), wherein said slot is provided in an insert which is removable from said enclosure.

Abstract: A diffuser (7) has a step (12) in the surface (9) just upstream of a point where boundary layer separation might occur. An acoustic jet (22) has a nozzle (17) immediately downstream of the step (12); the acoustic jet is driven (25) by a plurality of frequencies, one or more of which are subharmonics of another of them, and having different phases.

Abstract: A method and apparatus for ejecting a second fluid into the near-wall region of the boundary layer of a first fluid, so that the second fluid hugs the wall. This alone reduces drag by modifying the behavior of the near-wall structure, thereby reducing the frequency of burst and sweep cycles, even when the first and second fluids are identical. Further, one or more additives, such as polymer, surfactant, micro-bubbles, a combination thereof, and/or using a second fluid having an elevated temperature as compared to the temperature of the first fluid, may be used to achieve much greater drag reduction as well as lower dissipation rates than previously possible. The second fluid is ejected using a convex Coanda surface (7) and at a controlled velocity that is a small fraction of the velocity of the first fluid moving along the wall so that the flow lines of the second fluid are substantially aligned with the flow lines of the first fluid.

Abstract: The invention relates to a fluidic oscillator that is symmetrical about a longitudinal plane of symmetry, the oscillator comprising an opening enabling a fluid to enter into an “oscillation” chamber in the form of a two-dimensional fluid jet oscillating transversely relative to said plane of symmetry, an obstacle occupying the major portion of said oscillation chamber and possessing a front wall provided with a cavity situated facing said opening and swept over by the fluid jet in oscillation, wherein two side walls extend on either side of the opening and form a nozzle inside the oscillation chamber extending towards the obstacle and having a longitudinal dimension that is less than the distance between the opening and the front wall of the obstacle.

Abstract: A fluidic oscillator includes a member having an oscillation inducing chamber, at least one source of fluid under pressure, at least a pair of power nozzles connected to the at least one source of fluid under pressure for projecting at least a pair of fluid jets into the oscillation chamber, and at least one outlet from the oscillation chamber for issuing a pulsating or oscillating jet of fluid to a point of utilization or ambient. A common fluid manifold connected to said at least a pair of power nozzles. The shape of the power nozzle manifold forms one of the walls of the interaction or oscillation chamber. In some of the fluidic circuits, the length can be matched to fit existing housings. The power nozzle can have offsets which produce yaw angles in a liquid spray fan angle to the left or right depending on the direction desired.

Abstract: Fluidic oscillators with yawed liquid spray.