TUFLOW 1D Channels and Hydraulic Structures: Difference between revisions

When negative “M” values are used to deactivate 1D cross-sections, it changes the flow area, wetted perimeter, hydraulic radius, and the conveyance, while keeping the storage width unchanged. It is like inserting a thin plate at the middle of the channel, as shown in the figure below. This approach is preferred to retain the storage in the system but reduce the conveyance (e.g., off-stream storage not contributing to conveyance or sections either side of a constriction to generate better approach/departure velocities if using the Total Area approach). <br>

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[[File:Section deactivation M.png | 200px]]<br>

When using negative “N” (Manning’s n) or “R” (relative resistance factor) to deactivate the 1D cross-sections, it reduces both the flow area and the storage width, as shown in the figure below.<br>

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[[File:Section deactivation N R.png | 200px]]

 

==Calculating a 1d_bc head-discharge curve==