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Gas vortex flow meter

Gas vortex flow meter
Gas vortex flow sensor
gas flow meter
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Working principle
To install a vortex generator(bluff body)in the fluid,which can produces regular vortex at both sides of the vortex generator altematively.Such vortex is called Karman Vortex.Vortex trains are asymmetrically arranged at the downstream of the vortex geberator. Suppose the generating frequency of the vortex is f,the average speed of the incoming flow of the tested medium is V,the head-on width of the vortex generator is d,and the diameter of the flowmeter is D,and base on the principles of Karman Vortex,the following relations will be obtained:

cart（1）
                   f=StV/d           Formula (1)

Note:f- Suppose the generating frequency of the vortex
     St-Strouhal number
     V-average flow velocity at both sides of the vortex generator
d- the vortex geberator body width

Thus, by measuring the Carmen frequency of vortex separation of instantaneous flow rate can be calculated. Among them, Strouhal number ( St ) is a dimensionless unknown, Figure ( two) said the Strouhal number ( St ) and Reynolds number ( Re ) relationship.

                                                             chart（2）
In the curve St = 0.17straight section, whirlpool release frequency and velocity proportional to, namely the vortex flow sensor measurement range. As long as the detected frequency f can be obtained within the tube by the flow rate of the fluid, flow velocity and volume flow rate V. The measured pulse number and volume ratio, called the instrument constant ( K ), see type (2)
　                      K＝N/Q（1/m³）             Formula (2)
K＝Instrument constant（1/m³）
N＝Pulse number
Q＝Volume flow（m³）

Instrument installation dimensions: see figure ( five ), map ( six)