Question

-3 A tank full of liquid (p-1000 kg/m ,H-10 kg/(m s)) discharges to the atmosphere (K-0) through a smooth pipe of diameter D= 5 cm and variable length L whose outlet section is at a height h=10 m below the surface of the deposit. Between the deposit and the pipe a globe valve is placed in order to control the flow rate and maintain it at a constant value Q-0.01 m /s. Calculate the maximum pipe length beyond which it is not possible to control the flow rate using the globe valve. (The answer must be a numerical value in meters, with two significant figures) 20.00 18.00 Compuerta 16.00 O-Disco 14.00 -O-Globo 12.00 K 10.00 8.00 6.00 4.00 2.00 0.00 0.250.30 0.40 0.50 0.60 0.70 0.750.80 0.90 1.00 Fracción de apertura

Answer 1

Calculate the velocity of flow in the pipe. (0.01) (0.05)- -5.093 Calculate the Reynold number for the flow Re- (1000) (5.093) (0.05) (10-3 -2.55x10 Write the Bemoulli equation for the flow

+ _ + h--+-+ 0 +1h ( head loss) (5.09) 2(9.81) 10 K (10) (5.09) 2(9.81) -7.573 From given graph, for K-7.573, 0.4 Calculate friction factor for turbulent flow condition 6.9 1.8log 3.7 0.4 6.9 37255x10') f = 0.05063

Write the equation for head loss in the pipe. fL Substitute the values. (0.05063)L (0.05) 7.573 (7.573) (0.05) - 7.479 m 7.5 m