Pipe 200 metre long slopes drawn at one in hundred and tables from 600...
Solution:
Given data:
- Length of pipe = 200 m
- Slope of pipe = 1 in 100
- Diameter of higher end = 600 mm
- Diameter of lower end = 300 mm
- Discharge = 100 L/s
- Pressure at higher end = 60 kN/m^2
Conversion:
- Length of pipe = 200 m = 0.2 km
- Discharge = 100 L/s = 0.1 m^3/s
### Velocity at the higher end:
Velocity of flow (V1) can be calculated using the discharge formula Q = A1V1, where A1 is the area of cross-section at the higher end.
- Diameter of higher end (D1) = 600 mm = 0.6 m
- Radius of higher end (r1) = 0.6/2 = 0.3 m
- Area of cross-section at higher end (A1) = πr1^2 = 0.2827 m^2
Substituting the values in the formula, we get:
0.1 = 0.2827 x V1
V1 = 0.353 m/s
### Velocity at the lower end:
Velocity of flow (V2) can be calculated using the continuity equation A1V1 = A2V2, where A2 is the area of cross-section at the lower end.
- Diameter of lower end (D2) = 300 mm = 0.3 m
- Radius of lower end (r2) = 0.3/2 = 0.15 m
- Area of cross-section at lower end (A2) = πr2^2 = 0.0707 m^2
Substituting the values in the equation, we get:
0.2827 x 0.353 = 0.0707 x V2
V2 = 1.422 m/s
### Head loss due to friction:
Using the Darcy-Weisbach equation, the head loss due to friction can be calculated as:
hL = f x (L/D) x (V^2/2g), where f is the Darcy friction factor, L is the length of the pipe, D is the diameter of the pipe, V is the velocity of flow, and g is the acceleration due to gravity.
- Length of pipe (L) = 200 m
- Diameter of pipe at higher end (D1) = 0.6 m
- Diameter of pipe at lower end (D2) = 0.3 m
- Velocity of flow (V) = 1.422 m/s
- Acceleration due to gravity (g) = 9.81 m/s^2
The value of f can be calculated using the Colebrook equation as:
1/sqrt(f) = -2 x log10[(e/D)/3.7 + 2.51/(Re x sqrt(f))]
where e is the roughness height and Re is the Reynolds number.
Assuming the roughness height to be 0.03 mm for commercial steel pipes, the Reynolds number can be calculated as:
Re = (D1 + D2)/2 x V x ρ/μ
where ρ is the density of water and μ is the dynamic viscosity of water.
- Density of water
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