Under certain conditions vortices regularly form downstream of an object (bluff body) placed in a flowing fluid and shed on alternating sides of the stream. This phenomenon is commonly called a Karmen vortex street. The resultant vortex frequency is proportional to the fluid velocity and hence the flow rate can be calculated by counting the number of vortices being produced. This is achieved placing a pressure transducer, thermistor, or ultrasonic sensor just behind the bluff body which picks up the high and low pressure and velocity fluctuations as the vortices move past the sensor.
Vortices will not be shed regularly in medium to high viscosity fluids. Typically, a minimum Reynolds number of 10,000 is required to obtain optimum performance from a vortex flow meter.
- Vortex meters can be used for liquids, gases and steam
- Low wear (relative to turbine flow meters)
- Relatively low cost of installation and maintenance
- Low sensitivity to variations in process conditions
- Stable long term accuracy and repeatability
- Applicable to a wide range of process temperatures
- Available for a wide variety of pipe sizes
- Not suitable for very low flow rates
- Minimum length of straight pipe is required upstream and downstream of the vortex meter
NB.Vortex meters require sizing according to the flow rate being measured
Vortex flow meters are suitable for a variety of applications and industries but work best with clean, low-viscosity, medium to high speed fluids. Some of the main uses include:
- Custody transfer of natural gas metering
- Steam measurement
- Flow of liquid suspensions
- General water applications
- Liquid chemicals & pharmaceuticals
View our range of vortex flow meters here.
Use our product comparison tables for both industrial and compact vortex flow meters to guide you in selecting the right product for your needs.