Conclusions
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1.
The main regularities of the distribution of the three-dimensionless field of mean velocities, Reynolds stresses, and kinematic eddy viscosity over the cross section of rectilinear open channels of a trapezoidal form were found.
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2.
The existence was confirmed of steady transverse currents which intensify processes of convective mass transfer, have a considerable effect on the cross-sectional distribution of turbulent characteristics, redistribute the hydrodynamic forces over the wetted perimeter, causing the occurrence of their local extremes, are among the main causes of instability of the flow “in the large,” and, consequently, of meandering of channels, and thus act as one of the most important factors of channel-forming activity of a flow on rectilinear stretches of channels.
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3.
The distribution of the difference of normal Reynolds stresses, which figures in the main term of generation of transverse currents, in open channels of a trapezoidal form has a complex character determined by the interaction of the rigid and free boundaries, is determined mainly by the ratio of the transverse dimensions and value of the steepness of the side slopes, and considerably differs from the analogous distribution in rectangular pipes [13] and open channels [15].
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Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 48–52, September, 1989.
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Shnipov, F.D. Three-dimensional kinematic structure of a flow in trapezoidal channels. Hydrotechnical Construction 23, 557–563 (1989). https://doi.org/10.1007/BF01432069
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DOI: https://doi.org/10.1007/BF01432069