| 摘要 |
PURPOSE:To facilitate measuring the variation of pressure of a plane plate or the like, by measuring only the variation of sound pressure with a microphone arranged on the outside of a hollow water tank and obtaining the variation of water pressure on a basis of blade passing frequency components in the variation of sound pressure. CONSTITUTION:A pressure transducer is attached to the plane plate to detect the variation of water pressure. A microphone 11 is arranged just beside a propeller 5 on the outside of a body 1 of the hollow water tank to measure the variation of sound pressure. Respective blade passing frequency components DELTAP and DELTAQ of the variation of water pressure and the variation of sound pressure are plotted to draw a conversion diagram. As the result, only the variation of sound pressure is measured by the microphone 11 to estimate the variation of water pressure when the normal hollow water tank test is performed thereafter. |
