1D Bridges: Difference between revisions
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=Loss Theory=
==Contraction/Expansion Losses==
Energy loss is caused by the flow contraction due to the expansion of water after the vena-contracta inside a bridge section and the flow expansion downstream the bridge. The contraction/expansion loss coefficients (or the entry/exit loss coefficients) can be
* EntryC_or_WSa: the entry loss coefficients (default = 0.5).
* ExitC_or_WSb: the exit loss coefficients (default =
Note that the entry/exit loss coefficients are adjusted based on the equations in the figure below to consider the extent of flow contraction/expansion. For example, a clear spanning bridge over a stormwater channel does not cause any contraction/expansion. The change in approach velocity, structure velocity and the departure velocity are effectively the same, so the loss coefficients can be automatically reduced based on the following equations.
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[[File:Structure_Contraction_Expantion_Losses.png|600px]]
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