| 摘要 |
PROBLEM TO BE SOLVED: To make measurable the a flow in a wide range by forming a vortex generator in a cylindrical shape in which flat surfaces of a semi-cylindrical column make opposed to each other in parallel with a narrow width, and fixing the vortex generator in a straight circular cylinder of a vortex flowmeter. SOLUTION: The straight circular cylinder 3 is installed inside the cylindrical body in which flat surfaces of a semi-cylindrical column make opposed to each other in parallel with a narrow width. When the inside diameter of the right circular cylinder 3 is taken as D, the size of the cylindrical body is taken as (d), and the narrow width is taken as S, they are related to each other by expressions d/D=0.20 to 0.30 and S/d=0.09 to 0.11. As pressure fluctuation caused by vortex alternately emitted by the above arrangement strongly appears in a position where a boundary layer of a fluid causes a separation phenomenon on the surface of the vortex generator 2 near by a slit 9, a detection hole 6 is provided in the vicinity of the slit 9 of the semi-cylinder, and pierced through the right circular cylinder 3 to be communicated with a conduit 7. The surface pressure generated on the surface of the semi-cylinder is converted to an electric signal by a semiconductor pressure sensor 10, amplified and analyzed by an FFT analyzer 12 to calculate a flow by a computing device 13.
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