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 DarcyWeisbach relation, Eq. (6.30), holds  v v hf  eText Main Menu  f L V2
0
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 openchannel 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
f 1/2
Rh S1/2
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
 Sakar

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