大規模乱流場の特性の評価 : 第2報,乱流の諸統計量について

抄録

Characteristic features were experimentally evaluated with respect to a flow field with strong turbulence agitated by a mechanical turbulence generator. The energy density was increased in the lowest wave number range and the inertial sub-range was enlarged toward the smaller wave number. Anisotropy was introduced by the difference in the energy density level between the longitudinal and lateral spectral components there, but the difference became smaller as it flowed downstream. The decay rate was almost the same as that of the usual grid turbulence and became smaller as the Reynolds number increased. The probability density distribution of the lateral component of the velocity fluctuation was closely Gaussian, but the longitudinal component was slightly skewed.