Fluid vibrating type flowmeter

Abstract

A fluid vibrating type flowmeter has a nozzle disposed in a flow passage and defining a nozzle outlet plane extending perpendicular to the flow passage, an enlarged passage disposed downstream of the nozzle and including divergent inner wall surfaces symmetric about an axis of the nozzle, a target disposed centrally of the enlarged passage for obstructing straight movement of streams jetting out of the nozzle, and a constructed passage disposed downstream of the enlarged passage and having a smaller passage width than a rear end of the enlarged passage. Each of the divergent inner wall surfaces includes a main arcuate section continuous from the nozzle outlet plane, a straight diverging wall section continuous from the main arcuate section, and an auxiliary arcuate section continuous at an upstream end thereof from the straight diverging wall section and at a downstream end thereof with the constricted passage. The straight diverging wall section is formed as a common tangent of the main arcuate section and auxiliary arcuate section. The main arcuate section has a radium R and the auxiliary arcuate section has a radius r, these radii being in relations expressed by ##EQU1## wherein L is a distance between the nozzle outlet plane and the center of the auxiliary arcuate section, and x is a distance between the center of the auxiliary arcuate section and a passage axis.