Question

Çapı 50 mm olan sabit kesitli bir borudan 1.5 m/s hızla su akmaktadır. Boru girişindeki etkin basınç 590 kPa’dır. Borunun çıkışı, girişinden 25 m daha yüksekte ve atmosfer basıncındadır.
(ρsu=1000 kg/m3, g=9.81 m/s2)
a) Borunun giriş ve çıkışı arasındaki yük kaybını bulun. b) Boru yatay bir yüzey üzerine yerleştirilirse, akış hızı ile çıkış basıncı aynı kalacak şekilde giriş basıncını hesaplayın.

Water flows at a speed of 1.5 m/s through a fixed section pipe with a diameter of 50 mm. The effective pressure at the pipe Inlet is 590 KPA. The outlet of the pipe is 25 m higher than its entrance and is at atmospheric pressure.
(psu=1000 kg / m3, g=9.81 m / s2)
a) find the load loss between the input and output of the pipe

b) if the pipe is placed on a horizontal surface, calculate the input pressure so that the flow rate and the output pressure remain the same

Answer 1

Given data:

Water velocity at inlet = 1.5 m/s

Diameter of pipe = 50 mm

Pressure at inlet = 590 KPa

Oulet Pipe is 25 m higher than Inlet of the pipe.

Outlet pressure = 1 atm = 101.325 KPa

Concept: To determine loss in pipe we need to apply bernoulli's theorem between inlet and outlet of pipe.

According to conservation of mass,

A₁ = A₂    then   Velocity at inlet = velocity at outlet

(a) Total loss between Inlet and outlet of pipe = 24.81 m of water.

(b) If Pipe is placed horizontal, then to maintain same water flow and same pressure at outlet as in case (A),

Head loss in pipe will be same as in case A.

then bernoulli's theorem, reduces to

as         and Z₁ = 0 m and Z₂ = 0 (in Case B)    then by bernoulli's theorem

So for Case B, Required pressure at inlet = 344.43 KPa