はく離の前兆 : 流体工学,流体機械

概要

論文の詳細を見る
Surface pressure fluctuations before the onset of separation were investigated experimentally in order to find a precursor signal of separation. To generate managed separation, an inclined wall of a diffuser was opened with time at a constant angular velocity. Separation occurred when the angle of the inclined wall reached at 13 degrees in our experimental condition. Sinusoidal wave amplified with time before separation was detected by a pressure transducer mounted on the Inclined wall. The frequency of the wave was obtained by FFT analysis applied to small intervals in time of the pressure fluctuations. The particular frequency was found to be related to the instability wave due to an inflection point of velocity profile. This type of velocity profile appeared just before separation. Therefore, the sinusoidal wave can be regarded as a precursor of separation.
社団法人日本機械学会の論文
2001-09-25