Fluid Kinematics: Master the Fundamentals of Fluid Motion

Question 1

In fluid mechanics, what does the equation of continuity imply for incompressible flow?

Accepted Answer

Mass flow rate remains constant along a streamline.

Answer

Flow velocity is inversely proportional to the cross-sectional area.

Answer

Fluid acceleration is proportional to the pressure gradient.

Answer

Fluid density is uniform throughout the flow.

Question 2

In a flow field, the velocity vector is:

Accepted Answer

Tangent to the streamline at a given point

Answer

Normal to the streamline at a given point

Answer

Parallel to the streamline at a given point

Answer

Perpendicular to the streamline at a given point

Question 3

In a fluid flowing through a pipe of varying diameter, the fluid velocity will be maximum at:

Accepted Answer

Point of maximum diameter

Answer

Point of minimum diameter

Answer

Point where the diameter is constant

Answer

Velocity is uniform throughout the pipe

Question 4

The Bernoulli equation is an equation that relates:

Accepted Answer

Pressure, velocity, and elevation in a fluid flow

Answer

Force, mass, and acceleration in fluid flow

Answer

Energy, momentum, and density in fluid flow

Answer

Velocity, vorticity, and circulation in fluid flow

Question 5

Which of the following vector quantities characterizes the movement of a fluid element?

Accepted Answer

Velocity

Answer

Pressure

Answer

Density

Answer

Temperature

Question 6

Which dimensionless number quantifies the relative significance of viscous forces to inertial forces?

Accepted Answer

Reynolds number

Answer

Froude number

Answer

Mach number

Answer

Weber number

Question 7

Define an irrotational flow.

Accepted Answer

A flow with zero curl in its velocity field.

Answer

A flow with zero gradient in its pressure field.

Answer

A flow with uniform density field.

Answer

A flow with constant temperature field.

Question 8

What is the velocity profile for laminar flow in a circular pipe?

Accepted Answer

Parabolic

Answer

Linear

Answer

Exponential

Answer

Hyperbolic

Question 9

What is the purpose of the Reynolds transport theorem?

Accepted Answer

Relating the rate of change of a fluid property to its material derivative.

Answer

Calculating pressure gradient in a fluid.

Answer

Determining velocity field in a fluid.

Answer

Visualizing fluid flow.

Question 10

How do flow visualization techniques, like particle image velocimetry (PIV), help determine the velocity field of a fluid flow?

Accepted Answer

By tracking the movement of tracer particles within the flow

Answer

By measuring the pressure difference along the flow path

Answer

By observing the shape of streamlines in the flow

Question 11

Which of the following is NOT a fundamental concept of fluid kinematics?

Accepted Answer

Pressure gradients

Answer

Fluid motion

Answer

Velocity fields

Answer

Streamlines

Question 12

Which flow visualization technique is most suitable for visualizing the flow around a moving object?

Accepted Answer

Particle image velocimetry (PIV)

Answer

Smoke wires

Answer

Dye injection

Answer

Laser Doppler anemometry (LDA)

Question 13

What is the physical interpretation of the divergence of a velocity field?

Accepted Answer

Rate of volume change per unit time

Answer

Rate of mass flow per unit time

Answer

Rate of momentum change per unit time

Answer

Rate of energy change per unit time

Question 14

Which of the following is a necessary condition for irrotational flow?

Accepted Answer

Velocity field has zero curl

Answer

Velocity field is divergence-free

Answer

Velocity field is solenoidal

Answer

Velocity field is conservative

Question 15

What is the equation of continuity for an incompressible fluid?

Accepted Answer

∂u/∂x + ∂v/∂y = 0

Answer

∂u/∂x + ∂v/∂y = 1

Answer

∂u/∂x - ∂v/∂y = 0

Answer

∂u/∂x - ∂v/∂y = 1

Question 16

Which of the following is an example of a laminar flow?

Accepted Answer

Flow in a pipe at low Reynolds number

Answer

Flow around a car at high speed

Answer

Flow in a turbulent boundary layer

Answer

Flow in a jet engine

Question 17

What is the significance of the Reynolds number in fluid mechanics?

Accepted Answer

It measures the ratio of inertial to viscous forces

Answer

It determines the type of flow regime

Answer

It indicates the presence of turbulence

Answer

It is a measure of the fluid's viscosity

Question 18

What is the purpose of using streamlines in fluid kinematics?

Accepted Answer

To visualize the direction of fluid flow

Answer

To calculate the velocity of fluid flow

Answer

To determine the pressure distribution in a fluid

Answer

To measure the mass flow rate of a fluid

Question 19

A streamline is a line that is:

Accepted Answer

Tangent to the velocity vector at every point.

Answer

Where the fluid velocity is zero.

Answer

That connects points of equal pressure.

Answer

That is perpendicular to the velocity vector at every point.

Question 20

Vorticity is a measure of:

Accepted Answer

Local rotation of the fluid.

Answer

Flow rate.

Answer

Pressure gradient.

Answer

Shear stress.

Question 21

The Bernoulli equation is applicable to:

Accepted Answer

Inviscid, incompressible flows along streamlines.

Answer

Viscous, compressible flows along streamlines.

Answer

Inviscid, incompressible flows across streamlines.

Answer

Viscous, compressible flows across streamlines.