Oscillatory flowmeter

An oscillatory flowmeter yielding an output signal whose frequency is a linear function of flow rate, said flowmeter comprising:

• A. a meter body having a steering chamber therein, a power nozzle to project a jet stream of the fluid being metered into the chamber, and an output duct in line with the power nozzle to provide a fluid exit from the chamber;
• B. twin guides disposed in the chamber on either side of the power nozzle to define an interaction zone, the inner walls of the guides diverging outwardly from the power nozzle, the outer walls of the guides being spaced from the opposing sidewalls of the chamber to define feedback paths, each having an inlet at the downstream end of the related guide and an outlet at the upstream end forming a control nozzle adjacent the power nozzle;
• C. twin diverters disposed in the chamber on either side of the output duct, each diverter acting to split the jet stream which is emitted from the power nozzle and attaches itself to the inner wall of the related guide into a control stream which is diverted toward the inlet of the feedback path and an output stream which is directed toward the output duct, the control stream which flows through the feedback path and is discharged from its control nozzle acting in the interaction zone to deflect the incoming jet toward the inner wall of the other guide where the same hydraulic action is repeated, whereby the jet stream is switched alternately from guide to guide;
• and
• D. means to sense the resultant fluidic forces exerted on the diverters to produce said output signal.