Flow of Fluids Flashcards
(20 cards)
A valve that controls flow by means of a disk or wedge-shaped dam sliding at right angles to the direction of flow and seating lightly in the
valve body is a
A. gate valve B. globe valve C. butterfly valve D. orifice
A. gate valve
The equation that relates friction factor and Reynold’s number f=64/Re, holds to
A. smooth pipes
B. turbulent flow only
C. laminar and turbulent flow
D. laminar flow only
D. laminar flow only
The pressure drop in a rotameter is _____.
A. variable B. zero C. not measurable D. constant
D. constant
The ratio of viscosity of a fluid to that of water at 20oC is called the
A. kinematic viscosity
B. relative humidity
C. Newtonian viscosity
D. specific viscosity
D. specific viscosity
The person responsible counting the term “unit operation” is
A. Robert Pigford B. Gililand C. Arthur Little D. Treybal
C. Arthur Little
When pipe joints have to be broken from time to time for maintenance work, the connection that should be used is
A. nipples B. couplings C. welded joints D. flanges
D. flanges
For ideally incompressible fluid, the mach number will be
A. 0
B. 1
C. 1.5
D. 5
B. 1
Which of the following produces maximum pressure difference for transportation of gases?
A. vacuum pipes B. blowers C. fans D. compressors
D. compressors
A device for increasing the velocity of a fluid in steady flow is a
A. nozzle B. vent C. orifice D. compressors
A. nozzle
The resistance of a layer of fluid to flow over the next layer is measured by
A. viscosity
B. surface tension
C. friction factor
D. drag coefficient
A. viscosity
For Newtonian fluids, the shear stress is
A. constant
B. inversely proportional to rate of deformation
C. equal to shear rate of deformation
D. a linear function of the shear rate of deformation
D. a linear function of the shear rate of deformation
One of King Hero’s crowns was found to have weight 13 N in air. What is its specific gravity if Archimedes found it weighing 11.8 N in
water?
A. 10.83 B. 11.23 C. 12.43 D. 14.72
A. 10.83
Water flows in through an 8-in (ID=7.981 in) steel pipe at an average velocity of 6 ft/s. Downstream the pipe splits into an 8-in main and a
2 in (ID=2.067 in) bypass pipes. If the velocity in the bypass is twice the velocity of the main pipe, the volumetric flow rate (ft 3
/s) in the
main pipe is
A. 10.58 B. 5.29 C. 1.84 D. 0.25
C. 1.84
A water storage tank assumes the supply of water into a factory. Water is supplied to the tank through as booster pump installed in the
water line. The theoretical pump horsepower required is 3.25 hp. What is the monthly operation cost of the pump if electric power cost on
the average is PhP 3.27/kWh. The pump is 65% efficient and operates for 12 hr a day.
A. P 3300 B. P 5000 C. P 7000 D. P 12000
B. P 5000
Water at 60deg F flows through a 3-in schedule 40pipe. A pitot tube in the pipe shows a 3-inch Hg differential. If the Pitot tube is located
at the center of the pipe, what is the mass flow rate of the water [lb/s]?
A. 11.61 B. 14.24 C. 31.7 D. 37.1
C. 31.7
What size sharp-edge orifice [inches] was use in the flow of 120 gpm produced a 4-in Hg differential in a 4-in schedule 40 pipe? The fluid,
measured at 60degF, had a viscosity of 1 cSI and a specific gravity of 1.
A. 2.21 B. 1.35 C. 4.67 D. 2
A. 2.21
If the speed of a centrifugal pipe is doubled,, the energy requirement becomes approximately ____ times the original energy requirement.
A. 2 B. 4 C. 8 D. 10
C. 8
A pump requires 5Hp to transport the liquid from a lake to a reservoir. If pump efficiency is 65% and the electricity costs P0.30/kWh, what
is the monthly cost if the pump operates 12 hours per day?
A. P280 B. P680 C. P220 D. P620
D. P620
The distance between plates is Δy=0.5 cm, Δv=10 cm/s and the fluid is ethyl alcohol at 273 K having a viscosity of 1.77 cp. Calculate the
shear stress in dyne per square centimeters.
A. 0.210 B. 0.354 C. 0.540 D. 0.720
B. 0.354
Air at 250C [viscosity =0.010 cP] enters a section of 2-in schedule 40 commercial steel pipe. If the pressure drop falls by one-half, what
will be the new flow rate [kg/s]? Assuming isothermal flow, what is the pressure drop [kPa] in 60 m of pipe?
A. 350 B. 155 C. 101.3 D. 61
D. 61
