hydraulics lesson 11
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HYDRAULICS
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A.SUNA [email protected]
Homework project :hydraulicssakarya@gmail com
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Sakarya University, Engineering Faculty, Environmental Engineering Department, Esentepe Campus,
54187 SAKARYA
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•Understand how flow in open channels differs from flow inpipes•Learn the different flow regimes in open channels and
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AIM
Learn the different flow regimes in open channels and their characteristics
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n AIMLESSON 10: OPEN CHANNEL
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sSPECIFIC ENERGY
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z is the elevation head, P/ ρgy is the gage pressure head V2/2g is the velocity or dynamic head.
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SPECIFIC ENERGY
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sSPECIFIC ENERGY
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=Q= flow rate
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Q =
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for small channels with rough surfaces
for large channels with smooth surfaces
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Q =
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Mean values of the Manning coefficient n for water flow in openchannels*
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s EXAMPLE 1. Water is flowing in a weedy excavated earth channel of
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g ytrapezoidal cross section with a bottom width of 0.8 m, trapezoidangle of 60°, and a bottom slope angle of 0.3°. If the flow depth ismeasured to be 0.52 m, determine the flow rate of water through thechannel. What would your answer be if the bottom angle were 1°?
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EXAMPLE 2. Water is to be transported in an unfinished-concreterectangular channel with a bottom width of 1.22 m at a rate of 1.44m3/s. The terrain is such that the channel bottom drops 2 m per
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p p1000 m length. Determine the minimum height of the channel underuniform-flow conditions. What would your answer be if the bottomdrop is just 1 m per 1000 m length?
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EXAMPLE 3. Water flows in a channel whose bottom slope is 0.003 andwhose cross section is shown in the figure. The dimensions and theManning coefficients for the surfaces of different subsections are also givenon the figure. Determine the flow rate through the channel and the effectiveManning coefficient for the channel.
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Manning coefficient for the channel.
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http://landscape.ced.berkeley.edu/~kondolf/courses/LA222/lecture%2010-open%20channel%20flow.pdf
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