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Ali Hamza
Ali Hamza
Mechanical
04 Feb 2019

Open Channel Formulae for Uniform Flow:

OPEN CHANNEL FORMULAE FOR 

UNIFORM FLOW

o2/3 1/2RoS1nV 

Here,

V=Average flowvelocity 

R=Hydraulic radius 

So=Channel bedslope

V  C RS

C= Chezy’sconstant

n= Manning’s Roughness coefficient

For uniform flow in open channels, following formulae are widely used

1.Chezy’s Formula: Antoine de Chezy (1718-1798), a French 

bridge and hydraulic expert, proposed his formula in 1775.

2. Manning’s Formula: Rober Manning (An Irish engineer) 

proposed the following relation for Chezy’s coefficient

C= R16n

According to which Chezy’s equation can be written as