Energy losses in fluid flow systems are primarily caused by friction between the fluid and the pipe walls. This friction converts part of the fluid’s energy into heat, leading to a loss of useful mechanical energy.
What does the term “fluid kinematics” primarily deal with?
A Fluid motion
B Fluid viscosity
C Fluid density
D Fluid pressure
Fluid kinematics studies the motion of fluids without considering the forces that cause the motion. It focuses on describing the flow patterns, velocity, acceleration, and other characteristics of the fluid movement.
In fluid statics, what is the primary factor influencing pressure at a point in a fluid?
A Fluid temperature
B Fluid density
C Fluid surface tension
D Fluid velocity
In fluid statics, pressure at a point is primarily influenced by the density of the fluid and the height of the fluid above the point. According to hydrostatic pressure, pressure increases with depth due to the weight of the overlying fluid.
How does a reduction in pipe diameter affect the flow velocity in a fluid system?
A Depends on pressure
B No effect
C Increases velocity
D Decreases velocity
According to the continuity equation, if the pipe diameter decreases, the velocity of the fluid must increase to maintain a constant flow rate. This inverse relationship ensures that the flow rate remains consistent.
What is the primary cause of pressure variation in a static fluid?
A Fluid depth
B Fluid temperature
C Fluid density
D Fluid motion
In a static fluid, pressure increases with depth due to the weight of the fluid above. This is described by the hydrostatic pressure formula, where pressure is proportional to the fluid’s density and the height of the fluid column.
How is energy loss minimized in fluid flow systems?
A Increase pressure
B Increase fluid velocity
C Reduce fluid viscosity
D Use larger pipes
Energy losses due to friction are minimized in fluid flow systems by increasing the pipe diameter. Larger pipes reduce the velocity of the fluid and the frictional losses, improving the overall system efficiency.
What does the Bernoulli equation primarily relate in fluid dynamics?
A Pressure and density
B Velocity and mass
C Energy conservation
D Velocity and height
Bernoulli’s equation is based on the conservation of mechanical energy for a flowing fluid. It relates pressure, velocity, and elevation in an incompressible fluid, stating that the total energy remains constant along a streamline.
What is the effect of a fluid’s viscosity on its flow rate through a pipe?
A Increases flow rate
B Decreases flow rate
C No effect
D Varies with temperature
A higher viscosity increases internal resistance to flow, which slows down the fluid and reduces its flow rate. The resistance to flow is directly proportional to the fluid’s viscosity and the length and roughness of the pipe.
What is the primary focus of fluid dynamics in mechanical engineering?
A Fluid density
B Fluid temperature
C Fluid motion
D Fluid pressure
Fluid dynamics focuses on the behavior of fluids in motion, considering the forces that affect the fluid’s movement, velocity, pressure, and other dynamic properties. It is essential in designing systems like pipelines and pumps.
How does an increase in the temperature of a fluid generally affect its density?
A Increases density
B No effect
C Varies with pressure
D Decreases density
As the temperature of a fluid increases, the fluid expands, causing a decrease in its density. This is particularly noticeable in gases, where temperature changes cause significant variations in density.
In which type of flow is the velocity at every point along a streamline constant?
A Steady flow
B Turbulent flow
C Unsteady flow
D Laminar flow
Steady flow occurs when the velocity of the fluid at each point does not change over time. This ensures that the flow characteristics remain consistent as the fluid moves through the system.
What is the relationship between velocity and pressure in a fluid according to Bernoulli’s principle?
A Directly proportional
B Fluctuating
C Inversely proportional
D No relationship
According to Bernoulli’s principle, as the velocity of a fluid increases, its pressure decreases, and vice versa. This relationship is due to the conversion of energy from pressure to kinetic energy in the system.
How does a turbulent flow affect the efficiency of a fluid transport system?
A Increases efficiency
B Depends on fluid
C Decreases efficiency
D No effect
Turbulent flow is chaotic and irregular, causing higher friction and energy losses compared to laminar flow. This results in decreased efficiency in fluid transport systems, requiring more energy to maintain flow.
What does the term “hydraulic diameter” refer to?
A Pipe radius
B Effective diameter in non-circular ducts
C Cross-sectional area
D Flow velocity
The hydraulic diameter is used to calculate the flow resistance in non-circular ducts and is defined as four times the cross‐sectional area divided by the wetted perimeter. It helps in simplifying calculations for irregular flow paths.
What is the main purpose of using dimensional analysis in fluid mechanics?
A Simplify equations
B Determine pressure
C Measure flow rate
D Predict fluid behavior
Dimensional analysis simplifies complex fluid dynamics equations by eliminating units and reducing variables, making it easier to compare different flow scenarios and derive non-dimensional numbers like Reynolds number for flow predictions.