On hydraulic falls of single-layer flow

Hydraulic falls of single-layer flow are determined theoretically in terms of a time-dependent averaged AfKdV equation (AfKdV equation) in phase coordinate.From the theory of the present paper it was known that difference of the asymptotic mean IeveLs upstream and downsream at the subcritical cutoff points is just equal to a subcritical value of the AfKdV equation-2X.An experiment is carried out to examine the theoretical results.From rnmparison between theoretical and experimental results, it was shown that they are in good agreement.At the same time, it should be pointed out that the theory of the present paper is agreement with the experimental and numerical results of Forties and can be employed to find the generating properties of the precursor solitons at near-resonance.