Minimum Specific Energy and Critical Flow Conditions in Open Channels |
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Authors: | H. Chanson |
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Affiliation: | Reader, Environmental Fluid Mechanics, Dept. of Civil Engineering, The Univ. of Queensland, Brisbane QLD 4072, Australia. E-mail: h.chanson@uq.edu.au
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Abstract: | In open channels, the relationship between the specific energy and the flow depth exhibits a minimum, and the corresponding flow conditions are called critical flow conditions. Herein they are reanalyzed on the basis of the depth-averaged Bernoulli equation. At critical flow, there is only one possible flow depth, and a new analytical expression of that characteristic depth is developed for ideal-fluid flow situations with nonhydrostatic pressure distribution and nonuniform velocity distribution. The results are applied to relevant critical flow conditions: e.g., at the crest of a spillway. The finding may be applied to predict more accurately the discharge on weir and spillway crests. |
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Keywords: | Energy Critical flow Open channel flow Weirs Spillways Coefficients |
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