Abstract: A fluidic oscillator and a flowmeter comprising means (10, 14, 16) for forming a two-dimensional fluid jet and an obstacle (22) having a main cavity (26) swept by the oscillating jet, and secondary cavities (34, 36) on either side of the main cavity (26) enabling the radial extension of main vortices accompanying the oscillation of the jet to be made dependent on flow conditions. Applicable to the measurement of the velocity or flow rate of flowing fluid.

Abstract: A fluidic oscillator flowmeter in which a two-dimensional fluid jet oscillating transfersely relative to a plane of symmetry, P, sweeps over the bottom of a cavity, and in which the flow rate is determined by electronic means from a signal, S, corresponding to a differential pressure resulting from the difference between a pressure tapped off at a point, P.sub.3, located on the axis of intersection between the plane of symmetry, S, and the bottom of the cavity and a pressure resulting from tapping off the pressure at two points, P.sub.1 and P.sub.2, which are located symmetrically on respective sides of the plane of symmetry, S.

Abstract: A fluidic oscillator and a flow meter including such a fluidic oscillator comprising a fluid inlet suitable for forming a two-dimensional jet: an obstacle possessing a front portion in the form of a chamber facing the inlet on the path of the jet, said chamber including two walls that are symmetrical about a longitudinal plane of symmetry passing through said inlet, the walls meeting said plane; and means for increasing the pressure on each of the lateral flanks of the obstacle in the vicinity of the front portion in alternation and in a relationship with the oscillation of the jet between the walls of the chamber.