Unformatted text preview: oint 2 will lie on the same leg of the curve as E1. A subSupercritical approach flow Subcritical approach
y1 y2 V1 V2 ∆h Bump
depth v v | | ∆h
Ec (b) e-Text Main Menu Subcritical
bump 2 y2 yc Fig. 10.9 Frictionless two-dimensional flow over a bump: (a) definition sketch showing Froude-number
dependence; (b) specific-energy
plot showing bump size and water
depths. 1 ∆ h max y1 E2 E1 2.0 Specific
energy | Textbook Table of Contents | Study Guide Chapter 10 Open-Channel Flow critical approach, Fr1 1, will cause the water level to decrease at the bump. Supercritical approach flow, Fr1 1, causes a water-level increase over the bump.
If the bump height reaches hmax E1 Ec, as illustrated in Fig. 10.9b, the flow
at the crest will be exactly critical (Fr 1). If h
hmax, there are no physically
correct solutions to Eq. (10.39). That is, a bump too large will “choke” the channel and
cause frictional effects, typically a hydraulic jump (Sec. 10.5).
These bump arguments are reversed if the channel has...
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- Spring '08
- Fluid Dynamics, Fig, e-Text Main Menu, subcritical flow