平板乱流境界層対数速度分布領域における変動速度確率密度関数の特性

抄録

The log-law of a zero pressure gradient turbulent boundary layer is obtained by analyzing the similarity of the probability density functions of the streamwise velocity fluctuation. The slope of the log law is found to be constant, independent of the Reynolds number. We used the Kullback Leibler divergence of probability density function to identify the log-law region in experimental data. The outer edge of logarithmic region does not indicate the constant value when normalized by the boundary layer thickness. Rather, it is a function of the Reynolds number, and when the Reynolds number is suffucuently high, this value approaches to 0.2.