脉动压力为正态分布时瞬时畸变的随机统计特性及其最大值的预估

 <正> 通常认为,由脉动压力引起的瞬时畸变服从一定的随机分布规律。但至今,在国内外尚未见到有关瞬时畸变的幅值概率密度分布规律的确切描述的文献,即使在脉动压力为正态分布时也是如此。每当要利用瞬时畸变的概率分布规律时,人们总是假定它为正态分布。很显然,这样做有一定的近似性,如在最大瞬时畸变值的预估中,这种近似将会影响最大值的预估精度。

THE STATISTICAL PROPERTIES AND MAXIMUM VALUE OF INSTANTANEOUS DISTORTION CAUSED BY GAUSSIAN FLUCTUATING PRESSURE

In this paper, the statistical properties of instantaneous distoition of which the distribution of APD (amplitude probability density) of the fluctuating pressure is Gaussian are described, and the mathematical lelations between those propeiites, the steady-state distortion and the tuibulence are given. It shows that the APD of the instantaneous distortion is not always Gaussian and is determined only by the steady-state distortion index and the distortion of turbulence. The maximum value of Non-Gaussian instantaneous distortion can be estimated by the method proposed in a paper by present authors with the effects of the APD on the estimated maximum value considered. Comparison between the estimated results and the measured data by the authors shows that the accuracy of estimation of the maximum value can be improved while dispensing the assumption that the APD of instantaneous distortion is Gaussian.