| 摘要 |
PURPOSE: To measure an alternating particle velocity with good accuracy by a method wherein the alternating particle velocity is computed on the basis of a specific expression from pressure values at two places which are set arbitrarily at different distances of the upstream side or the downstream side in the movement direction of particles from a measuring target position. CONSTITUTION: A tube body 11 has the same inside diameter of a pipeline 20, an it is constituted so as to be attachable coaxially on the downstream side of the pipeline 20. Pressure sensors M1 , M2 are installed at the pipe wall of the pipe body 11 at a prescribed intervals Dx in the direction of a length Lx on the downstream side from a mounting position (3) to the pipeline 20. Regarding alternating particles in a medium which is passed to the left side from the right side, a pressure value is measured by the sensor M2 in a position (2), and a pressure value is then measured by the sensor M1 in a position (1). The pressure values are sent to a computer via a two-channel FET, and a velocity is computed. In the expression, U represents an alternating particle velocity (m/s), P1 represents a pressure Pa in a position at a distance of Lx +Dx (m) from a target position, P2 represents a pressure Pa in a position at a distance of Lx (m) from the target position,ρrepresents the density (kg/m<3> ) of the medium, C respresents the sound velocity (m/s) of the medium, (j) represents an imaginary unit, and K represents a wave number.
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