Open Channel Flow (Manning)
Hydraulics IS 4745:1968~2 min
Calculate discharge and velocity in open channels using Manning's formula.
Formula
V = (1/n) × R^(2/3) × S^(1/2)
Input Parameters
Concrete=0.013, Earth=0.025, Brick=0.015
Results
Flow Area
2.000m²
Wetted Perimeter
4.000m
Hydraulic Radius
0.5000m
Flow Velocity
1.532m/s
Discharge (Q)
3.065m³/s
Step-by-Step Method
- 1Calculate flow area A = B × y (rectangular channel).
- 2Wetted perimeter P = B + 2y.
- 3Hydraulic radius R = A/P.
- 4Velocity V = (1/n) × R^(2/3) × S^(1/2).
- 5Discharge Q = V × A.
Engineering Notes
- •Manning's n: concrete = 0.013, brick = 0.015, earth = 0.025, grass = 0.035.
Code Reference
IS 4745:1968
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