Unformatted text preview: n occur in long straight runs of constant slope and constant channel cross
section. The water depth is constant at y yn, and the velocity is constant at V V0. Let
the slope be S0 tan , where is the angle the bottom makes with the horizontal, considered positive for downhill flow. Then Eq. (10.2), with V1 V2 V0, becomes
hf z1 z2 S0 L (10.11) where L is the horizontal distance between sections 1 and 2. The head loss thus balances the loss in height of the channel. The flow is essentially fully developed, so that
the Darcy-Weisbach relation, Eq. (6.30), holds | v v hf | e-Text Main Menu | f L V2
Dh 2g Dh 4Rh Textbook Table of Contents (10.12) | Study Guide 10.2 Uniform Flow; the Chézy Formula 665 with Dh 4A/P used to accommodate noncircular channels. The geometry and notation for open-channel flow analysis are shown in Fig. 10.2.
By combining Eqs. (10.11) and (10.12) we obtain an expression for flow velocity
in uniform channel flow
V0 1/2 8g
0 (10.13) For a given channel shape and bottom roughness, the quantity (8g/...
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This note was uploaded on 10/27/2009 for the course MAE 101a taught by Professor Sakar during the Spring '08 term at UCSD.
- Spring '08