Unformatted text preview: way from uniform steep flow.
Figure 10.15b shows a mild slope which becomes even milder. The water depth
moves smoothly along an M-1 curve to the new (higher) uniform flow. There is no singular point, so gradually varied theory is adequate.
Figure 10.15c illustrates a steep slope which becomes less steep. The depth will
change smoothly along an S-3 curve to approach the new (higher) uniform flow. There
is no singular point. Compare with Fig. 10.15b.
Figure 10.15d shows a steep slope which changes to mild. It is generally impossible to revert back smoothly from supercritical to subcritical flow without dissipation.
A hydraulic jump will form whose position depends upon downstream conditions. Two
cases are illustrated: (1) a jump to an S-1 curve to reach a high downstream normal
depth and (2) a change to an M-3 curve and then a jump to a lower downstream depth.
Figure 10.15e illustrates a free overfall with a mild slope. This acts as a control section to the upstream flow, which then forms an M-...
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- Spring '08
- Fluid Dynamics, Fig, e-Text Main Menu, subcritical flow