Fluid Dynamics Quizzes: Master Fluid Mechanics Concepts

Question 1

In laminar pipe flow, the velocity profile is:

Accepted Answer

Parabolic

Answer

Uniform

Answer

Triangular

Answer

Rectangular

Question 2

In a steady, incompressible flow, the mass flux is:

Accepted Answer

ρv

Answer

ρv/μ

Answer

ρυ^2

Answer

ρv^3

Question 3

Which of the following is a dimensionless number that characterizes the relative importance of viscous and inertial forces?

Accepted Answer

Reynolds number

Answer

Mach number

Answer

Prandtl number

Answer

Froude number

Question 4

A fluid with a high dynamic viscosity will have:

Accepted Answer

High flow resistance

Answer

Low flow resistance

Answer

High thermal conductivity

Answer

Low thermal conductivity

Question 5

Bernoulli's equation is applicable to which type of flow?

Accepted Answer

Inviscid, incompressible flow

Answer

Viscous, compressible flow

Answer

Laminar, turbulent flow

Answer

Open-channel flow

Question 6

The boundary layer theory describes which region of a flow?

Accepted Answer

Region near a solid surface where viscous effects are significant

Answer

Region far away from a solid surface where inviscid flow dominates

Answer

Region where turbulence is most intense

Answer

Region where pressure gradients are negligible

Question 7

Which dimensionless parameter is used to characterise boundary layer thickness?

Accepted Answer

Reynolds number

Answer

Prandtl number

Answer

Nusselt number

Answer

Mach number

Question 8

What is the primary use of streamlines?

Accepted Answer

Visualising flow patterns

Answer

Calculating pressure gradients

Answer

Determining boundary layer thickness

Answer

Predicting drag forces

Question 9

Consider two pipes with the same diameter and length, but different materials. Which pipe will have a higher pressure drop if the same fluid flows through both at the same rate?

Accepted Answer

Pipe with higher roughness

Answer

Pipe with lower roughness

Answer

Cannot be determined without additional information

Question 10

Bernoulli's equation relates which fluid properties?

Accepted Answer

Pressure, velocity, and elevation

Answer

Density, viscosity, and velocity

Answer

Temperature, volume, and pressure

Answer

Mass, acceleration, and force

Question 11

In pipe flow, the pressure gradient acts in which direction relative to the flow?

Accepted Answer

Parallel to the flow direction

Answer

Perpendicular to the flow direction

Answer

Zero

Answer

Proportional to the flow rate

Question 12

Which of the following characterizes the boundary layer?

Accepted Answer

Low velocity near the surface

Answer

High velocity near the surface

Answer

Uniform velocity throughout

Answer

Turbulent flow

Question 13

A fluid with a high Reynolds number is likely to exhibit which flow regime?

Accepted Answer

Turbulent

Answer

Laminar

Answer

Incompressible

Answer

Viscous

Question 14

Viscosity is a fluid property that measures its:

Accepted Answer

Resistance to flow

Answer

Ability to store energy

Answer

Density

Answer

Thermal conductivity

Question 15

Incompressible flow occurs when which assumption is valid?

Accepted Answer

Density changes are negligible

Answer

Velocity changes are negligible

Answer

Pressure changes are negligible

Answer

Temperature changes are negligible

Question 16

In aircraft engineering, how does fluid dynamics contribute to optimizing engine efficiency, aircraft stability, and noise reduction?

Accepted Answer

Enhances engine efficiency by reducing drag through optimized airflow.

Accepted Answer

Improves aircraft stability by optimizing wing design for controlled flight.

Accepted Answer

Reduces noise pollution through strategic exhaust flow management.

Question 17

What is the significance of the Navier-Stokes equations in fluid dynamics?

Accepted Answer

They describe the motion of viscous fluids, considering velocity, pressure, and density.

Answer

They apply only to incompressible fluids.

Answer

They are a simplified version of the Euler equations, neglecting viscous effects.

Answer

They can be solved analytically for all flow conditions, providing exact solutions.

Question 18

Bernoulli's equation is applicable to:

Accepted Answer

Inviscid, incompressible, steady flow along a streamline

Answer

Turbulent flow in a boundary layer

Answer

Flow around a bluff body

Answer

Viscous, compressible flow in a pipe

Question 19

The pressure drop in a pipe due to friction is proportional to:

Accepted Answer

Length and diameter of the pipe, and fluid velocity

Answer

Diameter of the pipe

Answer

Density of the fluid

Answer

Velocity of the fluid

Question 20

The boundary layer thickness over a flat plate:

Accepted Answer

Increases with distance from the leading edge, and decreases with increasing fluid velocity

Answer

Remains constant with distance from the leading edge

Answer

Decreases with distance from the leading edge

Question 21

The Reynolds number is a dimensionless parameter used to:

Accepted Answer

Characterize the flow regime and predict the onset of turbulence

Answer

Determine the boundary layer thickness

Answer

Calculate the pressure drop in a pipe

Answer

Predict the onset of cavitation

Question 22

The drag force on a sphere is proportional to:

Accepted Answer

Square of the velocity and diameter of the sphere

Answer

Square root of the velocity

Answer

Velocity

Question 23

Which of the following is a common method for measuring fluid velocity?

Accepted Answer

Pitot tube and laser Doppler velocimetry (LDV)

Answer

Strain gauge

Answer

Thermocouple

Answer

Accelerometer

Question 24

Computational fluid dynamics (CFD) involves:

Accepted Answer

Solving the governing equations numerically using computer simulations

Answer

Conducting physical experiments in a wind tunnel

Answer

Using analytical methods to derive exact solutions

Answer

Measuring fluid properties using sensors