Flow of Fluids 2010 Special

TECHNOLOGICAL INSTITUTE OF THE PHILIPPINES – P CASAL FLOW OF FLUIDS COMPETENCY EXAM STUDENT NO. _______________________________ Date___________________ Provide the solution to select the correct answer. 1 A horizontal annulus is 27 ft. long. The outside radius of the inner cylinder is 0.495 in.; the inside radius of the outer cylinder is 1.1 in. A 60 % aqueous solution of sucrose (C12H22O11) is to be pumped through the annulus at 20˚C. At this temperature the fluid density is 80.3 lb/ft3 and its viscosity is 136.8 lbm / ft-hr. What is the volume rate of flow when the impressed pressure drop is 5.39 psi? a. 0.21 ft3/s b. 0.11 ft3/s c. 0.32 ft3/s d. 0.52 ft3/s 2. How many gallons of water at 68˚F can be delivered through a 1320 ft. length of smooth 6.00- in. i.d. pipe under a pressure difference of 0.25 psi? a. 5210 gal/hr b. 4070 gal/hr c. 1235 gal/hr d. 3245 gal/hr transport by byrd 3. The pressure exerted on a plane parallel to the direction of flow of a moving fluid. a. velocity pressure b. static pressure c. impact pressure d. pressure difference 4. The absolute pressure of water one meter below the surface of a lake is _______. a. 103 Pa b. 104 Pa c. 105 Pa d. 106 Pa 5. Calculate the flow of air, in cfm, measured at 60˚F and a pressure of 1 atm if air at 200˚F is forced through a long, circular flue 36 in. in diameter. A pitot-tube reading is taken at the center of the flue at a sufficient distance from flow disturbances to ensure normal velocity distribution. The pitot reading is 0.54 in. H2O and the static pressure at the point of measurement is 15.25 in. The coefficient of the pitot tube is 0.98. a. 11,000 cfm b. 15000 cfm c. 17000 cfm d. NOTG 6. A venturi meter is to be installed in a Schedule 40 4-in. line to measure the flow of water. The maximum flow rate is expected to be 325 gallons per minute at 60˚F. The 50-in manometer used to measure the differential pressure is to be filled with mercury, and water is to fill the leads about the mercury surfaces. The water T is to be 60˚F throughout. What will be the power required to operate the meter at full load? a. 4.5 hp b. 0.43 hp c. 0.94 hp d. NOTG 7. A centrifugal pump is used to take flue gas at rest and at a pressure of 29.0 in and a temperature of 200 ˚F and discharge it a pressure of 30.1 in and a velocity of 150 fps. Calculate the power needed to move 10000 std cfm of gas. The efficiency is 65% and the molecular weight of the gas is 31.3. a. 60.3 hp b. 75 hp c. 36 hp d. NOTG 8. A bed containing 36 tons of 100-mesh sharp sand is to be fluidised with air at 400 ˚C and a pressure of 17 atm abs in a cylindrical vessel 10 ft. in diameter. The ultimate density of the sand particles is 168 lb/ft3. The viscosity of the air at the operating conditions is 0.032 cP. Call g/gc unity. Calculate the critical superficial air velocity. a. 0.2 fps b. 0.14 fps c. 0.52 fps d. NOTG 9. Crude oil, specific gravity 60˚F/60˚F = 0.887, flows through the piping shown in the figure. Pipe A is 2 in. in diameter Schedule 40 pipe, pipe B is 3 in. Schedule 40, and each of pipes C is 1 ½ -in Schedule 40. An equal quantity of liquid flows through each of the pipes C. The flow through pipe A is 30 gpm. Calculate the mass velocity in pipe C a. 744 kg/m2-s b. 351 kg/m2-s c. 637 kg/m2-s d. NOTG 10. What pressure drop is required in order to pump water at 20˚C through a pipe 25 cm in diameter and length 1234 m at a rate of 1.97 m3 sec –1. The pipe is horizontal and contains four-standard –radius 90˚ elbows and two 45˚ elbows. a. 5.54 x 103 psi b. 4.63 x 103 psi c. 2.34 x 103 psi d. NOTG 11. How many gallons of water at 68˚F can be delivered through a 1320 ft. length of smooth 6.00- in. i.d. pipe under a pressure difference of 0.25 psi? a. 5210 gal/hr b. 4070 gal/hr c. 1235 gal/hr d. 3245 gal/hr transport by byrd