onlinechannel03.php:   Discharge in a partially full circular culvert
 Formulas

θ = 2 cos-1[1 - 2(y/D)]
A = (D2/8) (θ - sinθ)
P = rθ
R = A/P
Q = (k/n) AR2/3S1/2
V = Q/A
INPUT DATA:

Select:  

Pipe diameter D:  

Flow depth y:  

Bottom slope S:  

Manning's n:  

INTERMEDIATE CALCS:

Constant k:   

Flow area A:   

Wetted perimeter P:   

Hydraulic radius R:   

Relative depth y/D:   

Froude number [based on y]:   

OUTPUT:

Discharge Q:   

Flow velocity V:   

            

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