instructor: fluid mechanics and course code: dr. a. c

Instructor:Dr. A. C. Mandal

FLUID MECHANICS ANDRATE PROCESSES

Course code:ESO-204A

[Tutorial - 07]

Q-1: Oil with a density of 850 kg/m3 and kinematic viscosity of 0.00062m2/s isbeing discharged by a 5-mm-diameter, 40-m-long horizontal pipe from a storage tankopen to the atmosphere. The height of the liquid level above the center of the pipe is3 m. Disregarding the minor losses, determine the flow rate of oil through the pipe.

Q-2: Water at 10°C (ρ = 999.7kg/m3 and µ = 1.307 × 10−3kg/m − s) is flowingsteadily in a 0.20-cm-diameter, 15-m-long pipe at an average velocity of 1.2 m/s. De-termine (a)the pressure drop, (b)the head loss, and (c)the pumping power requirementto overcome this pressure drop.

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Alakesh

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Q-3: In fully developed laminar flow in a circular pipe, the velocity at R/2 (midwaybetween the wall surface and the centerline) is measured to be 6 m/s. Determine thevelocity at the center of the pipe.

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Q-4: Consider the flow of oil with ρ = 894kg/m3 and µ = 2.33kg/m− s in a 40-cm-diameter pipeline at an average velocity of 0.5m/s. A 300-m-long section of the pipelinepasses through the icy waters of a lake. Disregarding the entrance effects, determinethe pumping power required to overcome the pressure losses and to maintain the flowof oil in the pipe.

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Q-5: Air enters a 7-m-long section of a rectangular duct of cross section 15cm ×20cm made of commercial steel at 1 atm and 35°C at an average velocity of 7 m/s.Disregarding the entrance effects, determine the fan power needed to overcome thepressure losses in this section of the duct.

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Alakesh

Pencil




Q-6: A horizontal pipe has an abrupt expansion from D1 = 8cm to D2 = 16cm. Thewater velocity in the smaller section is 10 m/s and the flow is turbulent. The pressurein the smaller section is P1 = 300kPa. Taking the kinetic energy correction factor tobe 1.06 at both the inlet and the outlet, determine the downstream pressure P2, andestimate the error that would have occurred if Bernoulli’s equation had been used.

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Q-7: An orifice with a 2-in-diameter opening is used to measure the mass flowrate of water at 60°F (ρ = 62.36lbm/ft3 and µ = 7.536 × 10−4lbm/ft − s) through ahorizontal 4-in-diameter pipe. A mercury manometer is used to measure the pressuredifference across the orifice. If the differential height of the manometer is read to be 6in, determine the volume flow rate of water through the pipe, the average velocity, andthe head loss caused by the orifice meter.

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Q-8: A Venturimeter equipped with a differential pressure gauge is used to measurethe flow rate of water at 15°C (ρ = 999.1kg/m3) through a 5-cm-diameter horizontalpipe. The diameter of the Venturi neck is 3 cm, and the measured pressure drop is5 kPa. Taking the discharge coefficient to be 0.98, determine the volume flow rate ofwater and the average velocity through the pipe.

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Alakesh

Pencil




Q-9: The tank-pipe system of Fig. is to deliver at least 11m3/h of water at 20C tothe reservoir. What is the maximum roughness height ε allowable for the pipe?

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Q-10: In Fig. suppose that the fluid is carbon tetrachloride at 20C and p1 = 1100kPagage. What pipe diameter, in cm, is required to deliver a flow rate of 25m3/h?

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Q-11: A large room uses a fan to draw in atmospheric air at 20C through a 30-cmby 30-cm commercial-steel duct 12 m long, as in Fig. Estimate (a)the air flow rate inm3/h if the room pressure is 10 Pa vacuum and (b) the room pressure if the flow rateis 1200m3/h. Neglect minor losses.

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Alakesh

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Q-12: The reservoirs in Fig. are connected by cast-iron pipes joined abruptly, withsharp-edged entrance and exit. Including minor losses, estimate the flow of water at20C if the surface of reservoir 1 is 45 ft higher than that of reservoir 2.

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instructor: fluid mechanics and course code: dr. a. c

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