| 摘要 |
PURPOSE:To easily detect the flow velocity of a fluid based on the frequency of sounds corresponding to the flow velocity of the fluid by generating the sounds by periodically rotating the fluid. CONSTITUTION:When a fluid is sucked in a supplying passage 2a from an inlet 2b, the fluid spouts into a cylindrical body 1 in a direction A from an outlet 2a through an opened window section 1a at a speed higher than the flowing-in speed, since the cross-sectional area of the passage 2a becomes gradually smaller as going toward the outlet 2c. Then the fluid starts to rotate along the internal surface 13 of the body 1 and, when the fluid reaches a point D, the internal pressure of the body 1 rises, because the fluid spouting in the direction A obstructs the flow passage of the rotating fluid. When the internal pressure becomes higher than a prescribed value, however, the flowing direction of the spouting fluid is abruptly changed to another direction E and the fluid rotating in the body 1 is discharged in a direction F. As a result, the internal pressure of the body 1 abruptly decreases and the fluid from the outlet 2c spouts into the body 1 and raises the internal pressure. When such operations are repeated, sounds are produced and the flow velocity of the fluid is measured based on the frequency of the sounds. |
