Momentum Transfer Problems PDF

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Momentum Transfer problems (sana pumasa ako)

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1.For pipe a, b and c respectively

Bernoulli’s equation with frictional fluid flow and shaft work

1. Crude oil, S.G. = 0.888, flows through the piping show below. Pipe A is 50 mm Schedule 40, pipe B is 75 mm Schedule 40 and each of Pipe C is 38 mm Schedule 40. An equal quantity of liquid

a) 6049.34, 6049.34, 3024.67 kg/hr b) 0.965, 0.429, 0.835 m/s

flows through each of the pipe C. The flow through pipe A is c) 856.022, 380.278, 740.833 kg / (m^2 * sec) * answers are rounded off

6.82 m^3 / hr. Ignore measurements in figure below.

Calculate a. mass flow rate in each pipe b. Average linear velocity in each pipe c. Mass velocity in each pipe

2. Air is flowing through a horizontal tube of 2.54-cm diameter. What is the pressure drop per meter at this velocity given a

2.

1.073 m

temperature of 25C?

3. A pump takes water at 10°C from a large open reservoir and delivers it to the bottom of an open elevated tank (see figure below). The level of the tank averages 48.77 m (160 feet) above the surface of the reservoir. The pipe is 0.076 m in diameter and consists of 152.4 m of straight pipe, six elbows (90*), two gate valves (Wide open), and 2 tees. The pump delivers 0.00898 m3 . What is the horsepower consumed if the pump has a s mechanical

efficiency

of

55%

?

3. 9.18kW 9.14kW

N m2

or 1.1755

ρ=

999.73 kg 3

Kg , μ=1.3077 x 10 −3 m∗s

4. 1.895 x 105 Pa or 188,954.4299 Pa 4. Nitrogen gas at 25C is flowing in a smooth tube having an inside diameter of 0.010m at the rate of

9.0

kg . The tube is sec∗m2

200m long and the flow can be assumed to be isothermal. The pressure at the entrance to the tube is

5 2.0265 x 10 Pa .

2.71 x 105 kN 2 m

5.

Calculate the outlet pressure.

5. 98% sulphuric acid is pumped at 1.25kg/s through a 25 mm diameter steel pipe, 30m long, to a reservoir 12m higher than the feed point. Calculate the pressure drop in the pipeline μ=

2.5 x 10−2 kg , ρ=1840 kg /m 3 m∗s

6. How many gallons of water per minute at 20C can be delivered through a 400m length of smooth pipe 0.15m diameter with a pressure ρ=998.23

difference

of

1720

N/m^2

?

1.005 x 10−5 kg kg , μ= 3 m∗s m

7. A large high-pressure chemical reactor contains water at an absolute pressure of

1.38 x 107

N/m^2. And a temperature of

20C. A 0.07m inside diameter line connected to it ruptures at a point 3 meters from the reactor (as shown in the figure below.) What is the flow rate from the break? Assume commercial pipe.

6. 0.0042 m^3 / sec (67 gal / min ) Or 4.1864 x 10−3 (m^3)/s 4.1864 L/s 66.3558 gal(US) / min

7. 0.4230m 3 s

0.4246 m3 s

ρ=998.23

kg

−5

, μ= 3

1.005m∗s x 10 kg

8. 1.85x0.185 to 1.9mx1.9m 0.188m

8. A volumetric flow of air (14.2 m3/ min) is to be moved from an air conditioner to a building 243.8 m away. The air is at a temperature of 5°C and a pressure of 689.5 N/m2. Building pressure is 0 N/m2. What would be the dimension of a smooth square duct used to transport the air?

|¿|

1.688 x 103 P a ¿ |¿| 667 , 065.5557 P a¿ |¿| 688,474.0817 P a¿

Compressible flow of gases 1. Natural gas, which is essentially methane, is being pumped through a 1.0.16-m-ID pipeline for a distance of

5

1.609 x 10 m

(D1) at a rate of 2.077 kg mol/s. It can be assumed that the line is isothermal at 288.8K. The pressure 3

the line is

170.3 x 10 Pa

P2

at the discharge end of

absolute. Calculate the pressure

P1

at the inlet of the line. The viscosity of methane at 288.8K is −5

1.04 x 10

Pa∗s .

6.0019 m 1. V 2= s q1 =

(energy balances? Basta Bernoulli’s parin)

1.1947 m s

3

1. A 0.1524m diameter pipe is connected to a pipe with diameter of 0.2032m. If the average velocity in 0.1524m-pipe is 10.67

m , sec

what is the average velocity in the 0.2032m. Determine the mass flow rate, the weight flow rate, and volumetric flow rate.

2. – d W s ¿

14210.871 ( N∗m) s

2. The mass flow rate G of water through a pipe is 80.267

kg . s

¿ 8,526,522.6 N∗m

How much fluid energy flows through a section of this pipe in 10 minutes if at this section the pressure of the water is 172.4 kPa and its velocity equals 3.048

m ? s

3. 6,769.56 kW

3. The flow rate os a river is 28.3

m 3 /s . A reservoir creates a

4.

hydraulic turbine pumps are 80% efficient, how much potential

m s b) 17.2784 m

power in kilowatts can be generate at this site?

c) 0.00933

depth of water 3.48m above the intake to a power plant. Assume the

4. Water for a fire hose is being pum'ped from a lake 5 ft (1.524 m) below the ground level and the firemai1 is holding the nozzle 3.5 ft (1.067 m) above the ground. If the pump increases the pressure by 30 psi (206.8 kPa), and the head loss in the fire hose is 4 ft (1.219 m), Determine: a) The velocity (m/s) will the water have upon discharging from the nozzle b) If the fireman held the nozzle vertically upward, the heigh in meters the water will rise (ignoring air drag) c) if the nozzle is 2.54 cm in diameter, what is the volumetric discharge (m^3/s) d) the actual power (in kW) require to drive the pump if it is 85% efficient

a) 18.412

m3 s d) 2.2699 kW...