What is the principle of a vortex flow meter?
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I would like to ask: what is the principle of a vortex flow meter?
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This post was last edited by qugd on 2017-1-20 09:59. Have you ever seen vortices formed downstream behind the piers of some rivers, after the water has flowed past? There is a specific mathematical relationship between the flow rate of water during drifting and the number of vortices generated; the flow rate of water can be determined by the number of vortices formed or the frequency at which they appear. Similarly, gas flow in the air also generates a series of vortices behind obstacles. This is the famous Karman vortex street principle; the condition for the formation of a Karman vortex street is that the fluid flow must reach a certain range of Reynolds numbers. The following figures illustrate this principle and the formula for measuring fluid flow velocity.
These two graphs illustrate the relationship between vortex streets and flow velocity:
Great, this is really worth learning*!
May I ask, why is it called a vortex street? Why not simply call it a vortex flow? :lol
What kind of sensors are generally used to measure vortex frequency? Some mention temperature as a factor, while others refer to pressure; how sensitive must such sensors be in order to detect changes in vortices?
Any physical parameter that can detect the frequency variation of vortices can be used as a sensing method for vortex flow meters, but factors such as reliability, feasibility, and applicability need to be considered. These methods include detecting pressure, temperature, vibration, stress, the piezoelectric effect, the photoelectric effect, sound wave reflection, etc. I had a post quite some time ago that explained vortex flowmeters, and it included a description of the detection methods used