Hydraulic resistances and capacity of uniform aerated and nonaerated rapid flows in concrete channels: Fid-Bau Portal

Hydraulic resistances and capacity of uniform aerated and nonaerated rapid flows in concrete channels

Aivazyan, O. M.

Conclusions 1. Uniform rapid flows in concrete flumes, canals, and chutes, just as in smooth-walled and precast reinforced-concrete canals, obey an original law of hydraulic resistance, exressed by formula (4) with values of the constants K<0, w<0, z<0. 2. The indicated law of resistance and its analytical expression (4), which became known after publication of [2], are not taken into account by the recommendations on calculating the coefficients C or λ contained in current textbooks and standard references, which makes the latter unsuitable for calculating rapid flow in channels of the aforementioned categories. 3. For the example of concrete and smooth-walled channels in a wide range of slopes, the phenomenon of identity (v=idem) of the average velocities of the liquid phase of real aerated uniform rapid flows and hypothetical nonaerated flows in the same channels calculated by (4) for Q=idem was established. 4. The formula of the resistance coefficient (4) with parameters (10) and relation (16) of the aeration factor provide, with consideration of the identity of the velocities (v=idem) of the aerated and hypothetical nonaerated flows, a reliable calculation of aerated and nonaerated uniform rapid flows in concrete channels in a wide engineering range. 5. The hydraulic resistance coefficient and Chezy coefficient have practically constant values (24) in a wide region of uniform rapid flows in concrete industrial channels satisfying condition (23).