Vortex flowmeters, also know as vortex shedding flowmeters or oscillatory flowmeters, measure the vibrations of the downstream vortexes caused by a barrier in the moving stream.
The vibrating frequency of the vortex shedding is related to the velocity of the flow.
Flow metering principles - Orifice, Venturi, Flow Nozzles, Pitot Tubes, Target, Variable Area, Positive Displacement, Turbine, Vortex, Electromagnetic, Ultrasonic Doppler, Ultrasonic Time-of-travel, Mass Coriolis, Mass Thermal, Weir V-notch, Flume Parshall and Sluice Gate flow meters and more.
A limited comparison of flowmeter principles - regarding service, rangeability, pressure loss, typical accuracy, upstream pipe diameters, viscosity and relative costs.
Introduction to accuracy in flow measurement devices.
Introduction to the Strouhal Number
The vortex shedding frequency created around a bluff body and flow rate.