초음파를 이용한 와유량계 개발 연구

When a bluff body is placed in the flow, a series of alternate vortices is generated behind the bluff body, and vortex shedding frequency is proportional to fluid flow velocity. It is possible to measure fluid flow by detecting the vortex signal using ultrasonic wave. In order to develop a ultrasonic vortex flowmeter, a preliminary study has been performed by analyzing the vortex power spectrum generated by various shape of bluff bodies as well as by varying vortex detecting distance from the bluff body. Subsequently a ultrasonic vortex flowmeter lias designed and its performance has been evaluated by using compressed air. Uncertainty of the developed flowmeter was less than ±2.5% of the turn down ratio of 5.5:1.