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在水槽中测量了中等雷诺数下平板湍流边界层中的瞬时流向速度的时间序列 ,验证了Benzi提出的推广的自相似标度律 ,用子波变换将壁湍流脉动速度分解为多尺度湍涡结构的速度 ,研究了每一个尺度的湍涡速度结构函数的推广的自相似标度律· 主要结论如下 :湍流的统计性质是自相似的 ,这不仅适用于充分发展湍流 ,而且适用于中等雷诺数和低雷诺数湍流 ,而且具有相同的标度指数 ;推广的自相似标度律的适用的尺度范围远远大于惯性子区的范围 ,可以一直延伸至耗散区的尺度范围 ;推广的自相似标度律不仅适用于均匀各向同性湍流 ,也适用于剪切湍流如边界层湍流·
The time series of instantaneous flow velocities in the plate turbulent boundary layer at moderate Reynolds number were measured in a water tank. The self-similar scale law proposed by Benzi was verified. The wavelet transform was used to decompose the wall turbulent pulsation velocity into multi-scale turbulence The main conclusions of this paper are as follows: The statistical properties of turbulence are self-similar, which is not only suitable for the full development of turbulence, but also suitable for medium-sized Renault Number and low Reynolds number turbulence, and have the same scaling index. The applicable scale range of the extended self-similarity scale law is far greater than the range of the inertia sub-region and extends to the scale range of the dissipation region. The law of similar scales applies not only to isotropic turbulence but also to shear turbulence such as boundary layer turbulence