Self-aeration of open channel flow
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It is suggested that the cause of self-aeration in open-channel flow occurs when the turbulent normal stress exceeds the gravimetric pressure. A criterion for the start of self-aeration is established on this basis. A computational four-layer model of an aerated flow is proposed. It is also proposed that the equation of turbulent diffusion be used to calculate the distribution of air concentration along the normal to the bottom. Results are compared with experimental distributions of concentrations, and a satisfactory relationship is obtained.
Keywordschute self-aeration turbulent normal stress criterion for start of self-aeration distribution of air concentration over depth of flow
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