Ring type vortex flowmeter and method for measuring flow speed and flow rate using said ring type vortex flowmeter

摘要

A vortex flowmeter which is capable of measuring flow speed and flow rate both rapidly and precisely. The vortex flowmeter is composed of a ring-type bluff body situated in a pipe as a vortex shedder. The ring is bevelled at an acute angle at the inner and outer edges of the ring and the vortex shedding frequencies generated by the ring can be transformed to flow speeds and flow rates. The geometrical parameters G/W and D/W of the ring are G/W=0.50 to 0.53 and D/W=5.03 to 10.63, where G denotes the gap width between the outer edge of the ring and the pipe wall, W denotes the width of the ring, and D denotes the mean diameter of the ring. After these vortex shedding frequencies are nondimensionalized, they show a relationship with the Reynolds Numbers. The optimal streamwise location for installation of a pressure sensor is in the region of X/W=2.25 to 2. 84, where X denotes the axial distance from the leading surface of the ring frontal surface. The vortex shedding frequencies of the ring can be obtained from the wall pressure measurement. In addition, the present invention also provides a method that uses the vortex flowmeter to measure flow speed and flow rate.