1988 年 54 巻 497 号 p. 37-44
Length scales were experimentally determined for an artificially induced turbulence field with large turbulent intensities. The longitudinal and lateral integral scales were much larger than the values for conventional grid turbulence; and Taylor's micro scale was almost the same. The streamwise growth-rates of the micro scales were in good agreement with the theoretical value for isotropic turbulence, but the growth-rates of the integral scales were smaller than the theoretical values. The degree of the axisymmetric anisotropy was evaluated on the basis of the Rotta's model. The process of the return to isotropy was gradually carried out towards downstream, and the values of the main diagonal components of the anisotropy tensor became almost unvaried for X/M > 60. The skewness factor was proved to be dependent upon the turbulent intensity.