| Abstract: | Analysis of numerous experimental data reveals an influence of large vortices on the structure and characteristic parameters of flows. An approximate theory is proposed for describing the effect of large vortices on the pressure pulsations, the profiles of the pulsation velocities, the turbulence energy, and the velocity correlations (turbulence friction stresses). Large vortices are shown to have a long-range influence in that they induce pulsations of the pressure and the velocity at large distances, in particular in regions where transverse velocity gradients are absent (jet boundaries, symmetry axis, core of the initial section of a jet, etc.). When the theory is applied to the calculation of the turbulent characteristics of a mixing layer, a planar jet, a combustion jet, and a boundary layer on a flat surface, it is satisfactorily confirmed by the experimental data of a number of authors.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, p. 10–20, September–October, 1979.I thank A. B. Vatazhin, A. S. Ginevskii, T. A. Girshovich, and A. N. Sekundov for helpful advice. |
