1990 年 56 巻 522 号 p. 342-350
Three-dimensional energy and dissipation spectra were experimentally obtained in a large-scale turbulence field. The characteristic scales of turbulent eddies, the energy-containing eddy, lo, the largest locally isotropic eddy, lG, and the eddy of maximum dissipation, lD, were determined in the spectral profile. The energy spectrum became self-similar for k>1/lG but the lo scale was reduced in accordance with the streamwise decay of the turbulence energy. The lD scale was proven to be more appropriate as the scale of the energy-dissipative eddy than the Taylor microscale, λ. The energy spectrum started to depart from Kolmogorov's -5/3 low at η/lD∼0.15 and was most accurately approximated by the theoretical profiles with an exponential tail in the far dissipation range.