B8 Flashcards
Which of the following is a key characteristic of a fluid?
a) It resists deformation under stress.
b) It can only exist as a gas.
c) It continuously yields to tangential forces.
d) It has a fixed shape and volume.
It continuously yields to tangential forces.
Liquids are generally:
a) Compressible with significant changes in volume under pressure.
b) Practically incompressible and do not significantly change volume under pressure.
c) Gaseous at room temperature.
d) Capable of expanding to fill any container.
Practically incompressible and do not significantly change volume under pressure.
Real gases tend to:
a) Always follow the ideal gas law regardless of pressure.
b) Behave like ideal gases at high pressures.
c) Deviate from ideal gas behavior at high pressures, especially near the critical point.
d) Have constant specific heats regardless of pressure or temperature.
Deviate from ideal gas behavior at high pressures, especially near the critical point.
In the U.S. Customary Units system, which unit represents mass?
a) Pound-force
b) Slug
c) Kilogram
d) Newton
Slug
The density of a fluid is defined as:
a) The weight per unit volume.
b) The mass per unit volume.
c) The force per unit area.
d) The specific heat per unit volume.
The mass per unit volume.
Which of the following is true about the International System (SI) of units?
a) The base units include the pound and foot.
b) The kilogram is used for mass, and the meter is used for length.
c) The system is based on force instead of mass.
d) SI units do not include derived units like the joule and newton.
The kilogram is used for mass, and the meter is used for length.
What is the relationship between density and specific weight?
a) They are the same thing.
b) Specific weight is the mass per unit volume, while density is the weight per unit volume.
c) Specific weight is the weight per unit volume, and density is mass per unit volume.
d) They have no relationship.
Specific weight is the weight per unit volume, and density is mass per unit volume.
In the U.S. Customary Units system, which of the following is true about force?
a) Force is measured in pounds.
b) Force is calculated as mass times acceleration (F = ma).
c) The standard unit for force is kilogram.
d) Force is expressed in pascals.
Force is calculated as mass times acceleration (F = ma).
In the SI system, which unit is used for force?
a) Joule
b) Watt
c) Newton
d) Pascal
Newton
What is the SI prefix for 10^3?
A. Deci
B. Centi
C. Kilo
D. Milli
Kilo
What is the dynamic viscosity of water at 68°F (20°C) in SI units?
A. 0.001 Pa·s
B. 1 Pa·s
C. 0.1 Pa·s
D. 10 Pa·s
0.001 Pa·s
Which of the following properties is used to measure a fluid’s resistance to shear?
A. Density
B. Viscosity
C. Velocity
D. Pressure
Viscosity
What is the primary difference between Newtonian and non-Newtonian fluids?
A. Newtonian fluids are always liquids, while non-Newtonian fluids are gases.
B. Newtonian fluids have a linear relationship between shear stress and deformation, while non-Newtonian fluids do not.
C. Newtonian fluids have constant viscosity, while non-Newtonian fluids have constant pressure.
D. Newtonian fluids expand to fill their container, while non-Newtonian fluids do not.
Newtonian fluids have a linear relationship between shear stress and deformation, while non-Newtonian fluids do not.
What is the ratio of dynamic viscosity to mass density called?
A. Specific weight
B. Kinematic viscosity
C. Hydrostatic pressure
D. Bulk modulus
Kinematic viscosity
What is the approximate value of 1 standard atmosphere in psi?
A. 10 psi
B. 12 psi
C. 14.7 psi
D. 16 psi
14.7 psi
Which equation represents the law of conservation of mass applied to a flow process?
A. Bernoulli’s equation
B. Energy balance equation
C. Continuity equation
D. Darcy-Weisbach equation
Continuity equation
According to the text, the viscosity of gases:
A. Increases with increasing temperature
B. Decreases with increasing temperature
C. Remains constant regardless of temperature
D. Is unaffected by pressure
Increases with increasing temperature
Which unit is commonly used for pressure in both the SI and non-SI systems due to its practical importance?
A. Pascal (Pa)
B. Bar
C. Kilogram-force
D. Joule
Bar
What is the proper term for the pressure existing at a point within a static fluid body?
A. Dynamic pressure
B. Hydrostatic pressure
C. Atmospheric pressure
D. Vapor pressure
Hydrostatic pressure
What is the sum of specific internal energy and external pumping work called?
A. Stagnation energy
B. Specific enthalpy
C. Technical work
D. Bulk modulus
Specific enthalpy
Which property influences wave speed in liquids and is crucial in water hammer analysis?
A. Bulk modulus of elasticity
B. Dynamic viscosity
C. Specific enthalpy
D. Reynolds number
Bulk modulus of elasticity
Bernoulli’s equation applies to which type of fluid?
A. Real viscous fluids
B. Nonviscous, incompressible fluids
C. Compressible fluids
D. Newtonian fluids
Nonviscous, incompressible fluids
In the Darcy-Weisbach equation, the friction factor f:
A. Depends on the pipe material and flow type
B. Is constant for all flow conditions
C. Is always four times the Fanning friction factor
D. Depends on the Moody diagram only
Depends on the pipe material and flow type
What is the Reynolds number used for?
A. Calculating pipe roughness
B. Classifying flow as laminar or turbulent
C. Determining the bulk modulus
D. Measuring the dynamic viscosity
Classifying flow as laminar or turbulent
The Colebrook equation is widely used to calculate:
A. Laminar flow pressure losses
B. Friction factors in turbulent flow
C. The speed of sound in a fluid
D. The equivalent length of pipe
Friction factors in turbulent flow
Form losses in piping systems are due to:
A. Pipe bends, elbows, and valves
B. Viscosity of the fluid
C. Friction losses in laminar flow
D. Pressure variations due to fluid compressibility
Pipe bends, elbows, and valves
What does the Moody diagram represent?
A. Relationship between flow rate and velocity
B. Pipe material roughness and pressure drop
C. Friction factor for different flow regimes
D. Variation of enthalpy with velocity
Friction factor for different flow regimes
What is the purpose of the initial steady-state hydraulic analysis of a water system?
A. To confirm acceptable operation after construction
B. To calculate the final system flow balance
C. To obtain data required for purchasing system components
D. To create a finalized system description
To obtain data required for purchasing system components
What is the first step in the initial steady-state hydraulic analysis?
A. Calculate the pressure drop in the piping
B. Issue the system description and general arrangement drawings
C. Develop a system resistance curve
D. Calculate the flow balance in branching systems
Issue the system description and general arrangement drawings
In piping systems arranged in parallel, what remains constant for each flow path?
A. Total flow rate
B. Total pressure head loss
C. Flow velocity
D. Friction loss
Total pressure head loss
Which factor is not typically considered when selecting water flow velocities in a system?
A. Pipe material
B. Water quality
C. Weather conditions
D. Economic evaluation of costs
Weather conditions
The hydraulic grade line (HGL) represents:
A. The total energy in the system
B. The pressure and velocity heads combined
C. The static head along the pipe
D. The dynamic head at any point
The static head along the pipe
What is the assumption made in manual head loss calculations using graphs?
A. Flow velocity is constant across branches
B. Head loss varies with the square of velocity
C. Pressure remains constant throughout the system
D. Friction losses are negligible
Head loss varies with the square of velocity
Why are computerized calculations preferred for complex piping systems?
A. They require less input from engineers
B. They provide faster and more accurate results
C. They eliminate the need for schematic sketches
D. They are less costly than manual calculations
They provide faster and more accurate results
What must be consistent for all branches of a pipe junction?
A. Friction factor
B. Total energy
C. Velocity
D. Diameter
Total energy
Which of the following best describes the final steady-state hydraulic analysis?
A. It is performed before equipment purchasing to confirm operating modes
B. It ensures acceptable operation after reconciling as-built piping and equipment
C. It determines water quality and pump configurations
D. It eliminates the need for resistance curves
It ensures acceptable operation after reconciling as-built piping and equipment
What is the hydraulic grade line (HGL)?
A. The graphical representation of total pressure (Bernoulli head)
B. The graphical representation of static head along a pipe
C. The graphical representation of frictional losses
D. The graphical representation of velocity gradients
The graphical representation of static head along a pipe
What is the energy grade line (EGL)?
A. The graphical representation of the Bernoulli head (static + dynamic)
B. The graphical representation of static head only
C. The graphical representation of pressure drop due to friction
D. The graphical representation of the pipe diameter changes
The graphical representation of the Bernoulli head (static + dynamic)
As pipe diameter decreases, what happens to the flow velocity?
A. It decreases
B. It increases
C. It remains constant
D. It depends on the fluid temperature
It increases
Which cost increases with a reduction in pipe diameter?
A. Cost of pipe material
B. Pumping equipment cost
C. Labor costs for pipe erection
D. Fitting and support costs
Pumping equipment cost
What is the primary factor that makes oil flow calculations more complex than water flow calculations?
A. Oil’s compressibility
B. Oil’s temperature-dependent viscosity
C. Oil’s density consistency
D. Oil’s uniform physical properties
Oil’s temperature-dependent viscosity
The specific gravity of a substance is defined as:
A. The weight of the substance divided by its viscosity
B. The ratio of its weight to the weight of an equal volume of water
C. The density of the substance divided by the temperature
D. The volume of the substance per unit weight
The ratio of its weight to the weight of an equal volume of water
What is the API gravity of a 40% mixture of 10° API fuel and 60% of 15° API fuel?
A. 11°
B. 12°
C. 13°
D. 14°
12°
Why is viscosity considered the most important property when analyzing oil flow in pipes?
A. It determines the density of oil
B. It significantly affects pressure drop and flow rate calculations
C. It remains constant across temperature ranges
D. It simplifies flow calculations
It significantly affects pressure drop and flow rate calculations
What does the API gravity system help engineers calculate?
A. The compressibility of oil
B. The viscosity of oil at standard temperature
C. The specific gravity of fuel oil mixtures
D. The pressure drop in oil pipelines
The specific gravity of fuel oil mixtures
What is the recommended maximum temperature for heating heavy fuel oils in the bunkers to reduce viscosity for easier pumping?
A. 100°F (37.8°C)
B. 120°F (48.9°C)
C. 130°F (55°C)
D. 140°F (60°C)
130°F (55°C)
What type of chart is commonly used to determine the properties of blended oils?
A. Linear velocity chart
B. Viscosity blending chart
C. Reynolds number chart
D. Fanno line chart
Viscosity blending chart
Compressible flow in pipes involves variations in which fluid property?
A. Temperature only
B. Density only
C. Both pressure and density
D. Viscosity and velocity
Both pressure and density
What is the “choked” condition in compressible flow?
A. When the pipe diameter decreases to a minimum value
B. When the flow reaches sonic velocity at the pipe exit
C. When the pressure at the pipe exit is higher than the inlet
D. When friction losses are negligible
When the flow reaches sonic velocity at the pipe exit
Which of the following is typically used for long-distance gas transport?
A. Adiabatic constant-area flow
B. Isothermal flow with friction
C. Choked flow
D. Supersonic flow
Isothermal flow with friction
In Fanno line analysis, what remains constant along the length of the pipe?
A. Stagnation enthalpy
B. Sonic velocity
C. Specific volume
D. Heat transfer
Stagnation enthalpy
What is a simplified approach for analyzing frictional, adiabatic, constant-area flow of a perfect gas?
A. Viscosity blending chart
B. Fanno line analysis
C. API gravity calculation
D. Hydraulic grade line plotting
Fanno line analysis
What assumption is made for the Mach number in continuous isothermal flow?
A. Ma = 0
B. Ma must exceed 1
C. Ma is the limit for continuous isothermal flow
D. Ma is irrelevant for isothermal flow
Ma is the limit for continuous isothermal flow
What happens when the pipe length exceeds the limit for continuous isothermal flow?
A. The pipe temperature decreases
B. Choking occurs, reducing mass flow rate
C. The flow velocity increases indefinitely
D. The density of the fluid becomes constant
Choking occurs, reducing mass flow rate
In compressible steam systems, under what condition can density changes be neglected?
A. When the pressure drop is large
B. When the fluid behaves as an ideal gas
C. When density changes are small
D. When the fluid flow is adiabatic
When density changes are small
What is the recommended pressure drop limit for reheat piping in steam systems?
A. 3 to 4 percent of turbine exhaust pressure
B. 5 percent of turbine exhaust pressure
C. 7 to 9 percent of turbine exhaust pressure
D. 10 percent of turbine exhaust pressure
7 to 9 percent of turbine exhaust pressure
For extraction steam piping, the pressure drop should not exceed what percentage for low-pressure turbine stages?
A. 2 percent
B. 3 to 4 percent
C. 5 percent
D. 7 percent
5 percent
What is the venous contraction in the context of nozzles and orifices?
a) The point where the velocity of the jet is minimized.
b) The point where the jet reaches its maximum diameter.
c) The point where the jet reaches its smallest diameter and greatest velocity.
d) The distance the jet travels after leaving the nozzle.
The point where the jet reaches its smallest diameter and greatest velocity.
The coefficient of contraction Cc is defined as the ratio of:
a) The area of the jet at the vena contracta to the area of the orifice.
b) The velocity at the vena contracta to the velocity at the orifice.
c) The jet area to the pipe cross-sectional area.
d) The total pressure drop to the pressure drop at the orifice.
The area of the jet at the vena contracta to the area of the orifice
In the case of single-phase flow in nozzles, what happens when the fluid emerges from the nozzle?
a) The fluid immediately slows down and loses energy.
b) The fluid forms a jet with the same diameter as the nozzle.
c) The fluid forms a jet that is larger than the nozzle diameter.
d) The fluid rapidly loses velocity.
The fluid forms a jet with the same diameter as the nozzle.
What factor needs to be considered when installing a nozzle in the bottom of a tank?
a) The size of the orifice.
b) The fluid’s viscosity.
c) The distance from the bottom to the fluid’s free surface.
d) The temperature of the fluid.
The distance from the bottom to the fluid’s free surface.
What is the discharge coefficient (Cd) for an orifice or nozzle used for calculating flow rate?
a) The ratio of actual flow rate to theoretical flow rate.
b) The ratio of theoretical velocity to actual velocity.
c) The pressure difference across the nozzle.
d) The density of the fluid.
The ratio of actual flow rate to theoretical flow rate.
In the continuity equation for incompressible fluids, what remains constant?
a) Density and velocity.
b) Velocity and cross-sectional area.
c) Flow rate and temperature.
d) Pressure and flow area.
Velocity and cross-sectional area.
When calculating flow through a perfect gas in a nozzle, the isentropic flow assumption means:
a) The pressure remains constant across the nozzle.
b) There is no change in the stagnation enthalpy.
c) The flow is adiabatic with no friction or heat transfer.
d) The gas density does not change.
The flow is adiabatic with no friction or heat transfer.
What is the main purpose of using a calibration procedure for determining the discharge coefficient Cd in orifices or nozzles?
a) To ensure that the velocity of the fluid remains constant.
b) To account for variations in pressure drop across the nozzle.
c) To obtain an empirical value for the actual flow rate, improving accuracy.
d) To calculate the theoretical velocity at the exit.
To obtain an empirical value for the actual flow rate, improving accuracy.
What is the primary use of flow-restricting orifices?
a) To measure flow rates in high-pressure systems.
b) To provide a continuous small flow of fluid (bleeding).
c) To eliminate clogging in piping systems.
d) To increase fluid velocity in nozzles.
To provide a continuous small flow of fluid (bleeding).
The minimum allowable orifice size is typically recommended to be at least:
a) 1/8 inch to prevent clogging.
b) 1/4 inch to prevent clogging.
c) 1/2 inch to prevent clogging.
d) 1 inch to prevent clogging.
1/2 inch to prevent clogging.
The ASME test codes provide guidelines for measuring the flow of fluids using which three principal differential-pressure meters?
a) Flow nozzle, venturi tube, and pump.
b) Orifice, flow nozzle, and venturi tube.
c) Nozzle, valve, and orifice.
d) Orifice, venturi tube, and turbine meter.
Orifice, flow nozzle, and venturi tube.
What is the key characteristic of two-phase flow?
a) It involves the flow of two gases in a pipe.
b) It involves the simultaneous flow of gas and liquid phases.
c) It only occurs in single-component systems.
d) It only occurs in solid-liquid mixtures.
It involves the simultaneous flow of gas and liquid phases.
Which flow pattern is most commonly seen in vertical pipes with gas-liquid flow?
a) Stratified flow.
b) Bubbly flow.
c) Annular flow.
d) Slug flow.
Bubbly flow.
In upward concurrent flow in vertical pipes, when bubbles exceed 1 mm in diameter, they tend to:
a) Remain spherical and do not interact.
b) Become elongated but remain independent.
c) Interact with each other and form a packed configuration.
d) Maintain a constant size regardless of velocity.
Interact with each other and form a packed configuration.
The flow regime in two-phase gas-liquid flow is influenced by all of the following factors except:
a) Pressure drop along the pipe.
b) Geometry changes of the flow channel (e.g., bends, valves).
c) The chemical composition of the gas and liquid phases.
d) The flow direction (upward, downward).
The chemical composition of the gas and liquid phases.
Slug flow is characterized by:
a) A smooth and uniform flow of gas and liquid.
b) A series of gas plugs with blunt heads and flat tails.
c) Gas flowing in a single phase with a small amount of liquid.
d) Liquid moving in waves, without gas interaction.
A series of gas plugs with blunt heads and flat tails.
In slug flow, when the gas flow rate increases while maintaining a constant liquid flow rate, the flow pattern evolves toward:
a) Stratified flow.
b) Annular flow.
c) Plug flow.
d) Churn flow.
Churn flow.
When a liquid enters a heated pipe at a low flow rate and slightly lower than saturation temperature, what phenomenon may occur due to high wall temperatures?
a) Stratified flow
b) Mist flow
c) Slug flow
d) Churn flow
Mist flow
Which type of flow phenomenon can cause mechanical problems in offshore oil platforms due to liquid accumulation?
A) Stratified flow
B) Slug flow
C) Annular flow
D) Mist flow
Slug flow
In district heating systems, why should the hot water temperature be as high as possible?
A) To minimize pipe sizes and pumping costs
B) To avoid the need for insulation
C) To reduce pipe corrosion
D) To increase customer demand
To minimize pipe sizes and pumping costs
What determines the lowest possible pressure in a district heating system?
A) The pump power and efficiency
B) The hot water temperature and static head
C) The pipe material properties
D) The heat exchanger capacity
The hot water temperature and static head
What is the critical characteristic of the throat area in a converging-diverging nozzle?
A) It ensures minimum fluid density
B) It reaches sonic velocity (Mach number = 1)
C) It increases the pressure beyond ambient
D) It acts as a heat exchanger
It reaches sonic velocity (Mach number = 1)
What is the primary advantage of analyzing transient flow conditions in a piping system?
A) To optimize pressure losses
B) To prevent catastrophic failure due to water hammer effects
C) To increase the thermal efficiency of the system
D) To determine the viscosity of the fluid
To prevent catastrophic failure due to water hammer effects
In a simple converging nozzle, what is the relationship between exit velocity and fluid density?
A) Exit velocity is directly proportional to fluid density
B) Exit velocity is inversely proportional to fluid density
C) Exit velocity is independent of fluid density
D) Exit velocity varies randomly with fluid density
Exit velocity is inversely proportional to fluid density
What is the primary cause of water hammer in a piping system?
A) Slow valve opening
B) Rapid changes in flow rate
C) Increased pipe wall thickness
D) Reduced pipe diameter
Rapid changes in flow rate
