正冲击射流脉动壁压的正交分解与低阶近似

Study on wallpressure fluctuation of vertically impinging jet

为更好地了解冲击射流脉动壁压的统计特性,通过实验对其脉动壁压强度与频谱特性进行了研究,并对冲击射流脉动壁压时序信号的正交分解与低阶近似进行了探讨。根据实验结果得到了脉动壁压强度的拟合公式,其壁压表现为窄带低频过程。

For better understanding the statistic characteristics of wallpressure fluctuation, the intensity and spectrum function of vertically impinging jet were experimentally investigated, and the method of proper orthogonal decomposition and low order approximation was also used to study the sequential signals of the wall pressure fluctuation of impinging jet. A fitting formula describing the intensity of wallpressure fluctuation was obtained by test results. Characteristics of power spectrum function showed that the wallpressure variation is a narrowband, lowfrequency process.