A kind of flowmeters of reaction type is reported. The flowmeter is composed of a movable cup-shaped backet connected by some springs to a fixed flow-out pipe and coaxial inner flow-in pipe. And all of them are placed in a closed chamber. The displacement of the backet is measured by a differential transformer.
Incompressible perfect liquid flows in the flowmeter steadily, and the flow direction is reversed by the backet and so the momentum of the liquid increases by the action of the backet.
The reaction is proportional to the displacement of the backet and so the flowrate is proportional to the square root of the displacement.
The results of our experiments confirm fairly well this theoretical consideration.