Abstract: A vortex-controlled variable flow resistance device ideal for use in a backpressure tool for advancing drill string in extended reach downhole operations. The characteristics of the pressure waves generated by the device are controlled by the growth and decay of vortices in the vortex chamber(s) of a flow path. The flow path is designed to produce alternating primary and secondary vortices—one clockwise and one counter-clockwise—where the primary vortex is stronger and produces higher backpressure than the secondary vortex. This in turn generates alternating weak and strong pressure pulses in the drill string. The weak pulses may be barely perceptible so that the effective frequency of the pulses is determined by the stronger primary vortices.

Abstract: An agricultural irrigation system comprised of a plurality of unit pipes which constitute a water supply pipe line and another plurality of unit pipes which constitute a plurality water dispensing line each of whose respective pipe units are connected to respective center, valve/connectors which couple successive pipe units of the water supply pipe line.

Abstract: A fluidic oscillator includes a chamber having a common inflow and outflow opening into which a jet is issued in a generally radial direction. After impinging upon the far chamber wall the jet is redirected to form a vortex on each side of the incoming jet. The vortices alternate in strength and position to direct outflow through the common opening along one side and then the other of the inflowing jet. A spray-forming output chamber is arranged to receive the pulsating outflows from the aforementioned or other fluid oscillator and establish an output vortex which is thereby alternately spun in opposite directions. An outlet opening from the output chamber issues fluid in a sweeping spray pattern determined by the vectorial sum of a first vector, tangential to the output vortex and a function of the spin velocity, and a second vector, directed radially from the vortex and determined by the static pressure in the chamber.

Abstract: A fluidic oscillator includes a chamber having a common inflow and outflow opening into which a jet is issued in a generally radial direction. After impinging upon the far chamber wall the jet is redirected to form a vortex on each side of the incoming jet. The vortices alternate in strength and position to direct outflow through the common opening along one side and then the other of the inflowing jet. A spray-forming output chamber is arranged to receive the pulsating outflows from the aforementioned or other fluid oscillator and establish an output vortex which is thereby alternately spun in opposite directions. An outlet opening from the output chamber issues fluid in a sweeping spray pattern determined by the vectorial sum of a first vector, tangential to the output vortex and a function of the spin velocity, and a second vector, directed radially from the vortex and determined by the static pressure in the chamber.

Abstract: A fluidic oscillator includes a chamber having a common inflow and outflow opening into which a jet is issued in a generally radial direction. After impinging upon the far chamber wall the jet is redirected to form a vortex on each side of the incoming jet. The vortices alternate in strength and position to direct outflow through the common opening along one side and then the other of the inflowing jet. A spray-forming output chamber is arranged to receive the pulsating outflows from the aforementioned or other fluid oscillator and establish an output vortex which is thereby alternately spun in opposite directions. An outlet opening from the output chamber issues fluid in a sweeping spray pattern determined by the vectorial sum of a first vector, tangential to the output vortex and a function of the spin velocity, and a second vector, directed radially from the vortex and determined by the static pressure in the chamber.