Calculate the discharge for a stoneware sewer, running full. The diameter of the sewer is200 mm and it is laid at a slope of 1 in 72. Take n = 0.013 inManning's
formula
The Manning's formula for flow in an open channel is:
Q = (1.49/n) * A * R^(2/3) * S^(1/2)
Where:
Q = Discharge (m^3/s)
n = Manning's roughness coefficient (0.013 for stoneware sewer)
A = Cross-sectional area of flow (m^2)
R = Hydraulic radius (m)
S = Slope of the channel
Slope = 1/72 = 0.0139
First, calculate the cross-sectional area of flow:
A = π * (D/2)^2
A = π * (0.2/2)^2
A = π * 0.1^2
A = 0.0314 m^2
Next, calculate the hydraulic radius:
R = A/P
P = Wetted perimeter = π * D
R = 0.0314 / (π * 0.2)
R = 0.0314 / 0.628
R = 0.05 m
Now, substitute the values into the Manning's formula:
Q = (1.49/0.013) * 0.0314 * 0.05^(2/3) * 0.0139^(1/2)
Q = 114.62 * 0.0314 * 0.0323 * 0.117
Q = 0.14 m^3/s
Therefore, the discharge for the stoneware sewer running full is 0.14 m^3/s.