Abstract: A low pressure fluidic oscillator having an oscillation chamber having a centerline, and a pair of mutually facing and complementary-shaped sidewalls, planar top and bottom walls, upstream end and downstream end walls. An input power nozzle is formed in the upstream end wall having a width P.sub.W and a depth PD.sub.D, for issuing a jet of liquid into the oscillation chamber and forming alternately pulsating vortices in the oscillation chamber on each side of the jet, respectively. An outlet opening is formed in the downstream end wall and substantially axially aligned with the power nozzle. A pair of short sidewalls diverge in a downstream direction from the outlet opening. The distance from the power nozzle to the outlet opening being L. A slot is formed in at least one of said top and bottom walls, the slot having a slot centerline which is spaced upstream from the outlet opening a distance from about the edge of the downstream end of said oscillation chamber to about 0.48L.

Abstract: An apparatus for calculating fluid flow in a channel, comprising a probe member which detects fluid depth in the channel; a mechanism for measuring average fluid velocity in the channel; a mechanism for correcting the detected fluid depth based upon the measured average fluid velocity in order to account for drawdown; and a mechanism for calculating average flow rate based upon the average fluid velocity measurement and the corrected fluid depth value.

Abstract: A fluidic oscillator which is free of feedback passages has an oscillation chamber having a length greater than its width, a pair of mutually facing and complementarily-shaped sidewalls and planar top and bottom walls, and first and second end walls. An input power nozzle is formed in said first end wall having a width W and a depth D, for issuing a stream of fluid into the oscillation chamber, and form alternately pulsating, cavitation-free vortices in said oscillation chamber on each side of the stream. An outlet opening formed in the downstream end wall and axially aligned with the power nozzle and has a width and depth such that internal pressure in the oscillation chamber is greater than ambient. The outlet wall is hingedly connected to a chamber wall and the chamber is such that it can be molded with the outlet wall hingedly connected thereto in one molding.

Abstract: A fluidic oscillator which is free of feedback passages has an oscillation chamber having a length greater than its width, a pair of mutually facing and complementary-shaped sidewalls, planar top and bottom walls, and first and second end walls. An input power nozzle is formed in said first end wall having a width W and a depth D, for issuing a stream of fluid into the oscillation chamber, and form alternately pulsating, cavitation-free vortices in said oscillation chamber on each side of the stream. An interconnect passage or channel proximate the downstream end wall enlarges the sweep angle and improves periodicity of the oscillations. The outlet wall is hingedly connected to a chamber wall and the chamber is such that it can be molded with the outlet wall hingedly connected thereto in one molding and forms one side of the interconnect passage or channel.

Abstract: A powder spray gun comrpises a tubular housing having ambient air flow passages located in the side wall thereof medially of the opposite ends. A pair of air flow amplifiers are mounted in the housing on opposite sides of the ambient air flow passages and are so oriented that compressed air supplied to the upstream one of these amplifiers, the so called suspension amplifier, is operable to draw ambient air into the outlet end of the suspension amplifier, and compressed air supplied to the downstream amplifier, the so called pattern amplifier, is operable to draw ambient air into the inlet end of the pattern amplifier. The amplifiers are secured within the housing by end caps which are sealingly secured onto the ends of the housing by bayonet pin and slot connectors.

Abstract: There is disclosed a fluidic oscillator in which a stream of fluid is directed against a barrier member in an oscillation chamber. The barrier member serves as one wall of the oscillation chamber and in conjunction with other shaped wall surfaces of the oscillation chamber creates a pair of alternately pulsating control vortices for causing the fluid in the power stream to pass alternately to a pair of outlet passages. The vortices alternate both in strength and in a phase opposition to control flow of the jet stream in alternate fashion through the outlet passages. In a preferred embodiment of the invention, the pair of outlet passages are on opposite sides of the barrier member and converge to a common outlet to thereby provide a fan spray as the outlet passages alternate in the passage of the stream of fluid therethrough to the common outlet.

Abstract: A method and apparatus is disclosed, in the presently preferred embodiment, for applying powdered adhesive to non-woven fabric material. The apparatus includes a novel powder spray gun wherein there is an air flow amplifier contained within the gun for accelerating the velocity of powder emitted from the gun and sprayed onto the top of a conveyorized web of the fabric material. The apparatus also includes a novel system for supplying powder to the spray gun, which system includes a first powder pump, a back-up pump and a control circuit responsive to detection of reduced powder flow to the gun to switch supply from the first pump to the back-up pump.

Abstract: A powder spray gun and method of spraying powder are disclosed wherein an air flow amplifier is contained within the gun and is operable to draw ambient air into the gun and to impact air entrained powder passing through the gun with a high velocity stream of compressed air so as to accelerate the velocity of powder emitted from the gun.

Abstract: A liquid spray is characterized by a liquid jet which is cyclically deflected at a high frequency such that it breaks up into a fan-shaped spray pattern in which the fluid distribution and droplet size can be controlled. Jet deflection is accomplished with energy in the pressurized liquid itself. In a preferred embodiment, the spray is produced by a fluidic oscillator, of the type having a flow-reversing interaction region terminated by an outlet throat from which outlet walls diverge, configured to establish a static operating pressure at the upstream end of the interaction region which is positive relative to the pressure in the outlet region.

Abstract: A fluid oscillator for producing pulsations in a flow of fluid, having a housing with a fluid inlet channel for connection to a supply of fluid under pressure, a fluid outlet channel, and a diaphragm valve which alternatively opens and closes causing intermittent flow of fluid from the fluid inlet channel to the fluid outlet channel. The valve opens due to the fluid supply pressure in the fluid inlet channel and the valve closes due to a reduction in pressure caused by the inertia of the fluid in the fluid outlet channel. A pressure accumulator is located adjacent to the inlet channel to absorb fluctuations in fluid pressure in the inlet channel. An elastic separator element is located in the housing to define a gaseous compartment in the pressure accumulator, so that pressure fluctuations in the fluid inlet channel are generally absorbed or attenuated by compression and expansion of the gas in the accumulator.