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AFTER |
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DAMPING |
![]() (Write this 0.75% down for your use in your size calculation). |
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A "vortex shedding meter" is simple. You have seen the principle at work, when you went river fishing, or took a boat out with oars or a paddle. The faster the flow, the greater the rate that eddies were created round the edge of a stump into a backwater. The faster you rowed or paddled the more little eddies or vortexes, came off the end of your blade.In principle a "vortex meter" is a blade with a sharp edge to a flat backside.
The flow goes over the blade, and breaks into eddies of vortexes over the sharp edge leading to the back side. The more frequent the eddies, the faster the flow.
The backside has a hole in it, and inside the hole there is a sensor that senses small pressure fluctuations. The vortexes are minute low pressure disturbances, they are like little anticyclones. The meter counts them, and reads out the corresponding flow rate to which it has been calibrated.For this meter to be enabled to give you useful readings, you should first fix your system to feed
your meter with a generally smoothed flow. When you send a smooth flow to it, it will read a constant stream of vortexes. If your flow also has pressure pulses in it, the meter will also be confused.
It is generally advisable to keep the disturbances down to less than 0.75% of the theoretical
steady state condition.
UNDERSTANDING FLOW OR PRESSURE PULSATION
WAYS TO GO
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