阵列缝隙下弱抽吸流动的功率谱特性研究

Study on Power Spectrum Characteristics of Weak Suction Flows With Array Blades

基于安装纵向阵列叶片时T型通道中受弱抽吸作用最强的测量截面流向速度信号,研究了不同法向位置和不同主流速度、抽吸比工况的功率谱特性,发现距离壁面越远,弱抽吸作用对功率谱的影响程度减小,功率谱密度也减小,对应的惯性子区范围则增大;当主流速度一定时,抽吸比增大,对层流底层的破坏作用则减小,使得功率谱密度也减小,对应的惯性子区范围亦增加;当抽吸比一定时,主流速度增加,功率谱密度也增加,对应的惯性子区则不受影响。研究结果揭示了弱抽吸作用对层流底层的影响机理。

The streamwise velocity signals of the strongest section affected by weak suction in the T-channel with vertical array blades were selected to investigate their power spectrum characteristics under the conditions of different wall-normal positions,different cross velocities and suction ratios.It is found that further away from the wall,the effect of weak suction on the power spectrum will be reduced,and the power spectral density is also reduced so that the corresponding inertia sub-region range will be enlarged.When the mainstream velocity is constant,the suction ratio increases,the laminar sub-layer will be weakly destroyed,resulting in the decrease of the power spectral density,and the corresponding inertia sub-region will be enlarged.When the suction ratio is constant,the mainstream velocity increases,the power spectral density also increases,but the corresponding inertia sub-region is not affected.The results reveal the mechanism of the effect of weak suction on the laminar sub-layer.