FLUID MECHANICS FUNDAMENTALS
AND APPLICATIONS - ADVANCED
ASSESSMENT QUESTIONS AND
ANSWERS
1. For a Newtonian fluid in a steady, fully developed laminar flow through a horizontal pipe,
what is the ratio of the maximum velocity to the average velocity?
A. 1.33
B. 1.50
C. 2.00
D. 2.50
Answer: C
Conceptual Explanation: For laminar flow in a pipe (Hagen-Poiseuille flow), the velocity
profile is parabolic, and the maximum velocity at the centerline is exactly twice the average
velocity.
,2. Which term in the Navier-Stokes equations accounts for the rate of change of momentum
due to the movement of fluid from one location to another?
A. Convective acceleration term
B. Local acceleration term
C. Pressure gradient term
D. Viscous dissipation term
Answer: A
Conceptual Explanation: The convective acceleration term (u · ∇)u represents the effect
of the fluid’s velocity field changing as the fluid particle moves in space.
3. In the context of the Reynolds Transport Theorem, what does the ‘System’ represent?
A. A fixed region in space
B. A volume that can deform but not move
C. A quantity of matter of fixed identity
D. A flow field with varying density
Answer: C
Conceptual Explanation: A system is defined as a specific mass of fluid that remains the
same throughout the process, unlike a control volume which is a region in space.
4. What is the physical meaning of the Weber Number in fluid mechanics?
A. Ratio of inertial forces to gravitational forces
, B. Ratio of pressure forces to viscous forces
C. Ratio of inertial forces to surface tension forces
D. Ratio of buoyancy forces to surface tension
Answer: C
Conceptual Explanation: The Weber number is a dimensionless number that
characterizes the importance of surface tension relative to inertia, crucial for droplet and
bubble analysis.
5. Under what condition is the stream function (ψ) defined for a flow field?
A. The flow must be irrotational.
B. The flow must be steady.
C. The flow must satisfy the continuity equation.
D. The flow must be inviscid.
Answer: C
Conceptual Explanation: The stream function is mathematically defined such that it
automatically satisfies the continuity equation for 2D incompressible flows.
6. What happens to the stagnation pressure across a normal shock wave in a compressible
flow?
A. It increases.
B. It remains constant.
AND APPLICATIONS - ADVANCED
ASSESSMENT QUESTIONS AND
ANSWERS
1. For a Newtonian fluid in a steady, fully developed laminar flow through a horizontal pipe,
what is the ratio of the maximum velocity to the average velocity?
A. 1.33
B. 1.50
C. 2.00
D. 2.50
Answer: C
Conceptual Explanation: For laminar flow in a pipe (Hagen-Poiseuille flow), the velocity
profile is parabolic, and the maximum velocity at the centerline is exactly twice the average
velocity.
,2. Which term in the Navier-Stokes equations accounts for the rate of change of momentum
due to the movement of fluid from one location to another?
A. Convective acceleration term
B. Local acceleration term
C. Pressure gradient term
D. Viscous dissipation term
Answer: A
Conceptual Explanation: The convective acceleration term (u · ∇)u represents the effect
of the fluid’s velocity field changing as the fluid particle moves in space.
3. In the context of the Reynolds Transport Theorem, what does the ‘System’ represent?
A. A fixed region in space
B. A volume that can deform but not move
C. A quantity of matter of fixed identity
D. A flow field with varying density
Answer: C
Conceptual Explanation: A system is defined as a specific mass of fluid that remains the
same throughout the process, unlike a control volume which is a region in space.
4. What is the physical meaning of the Weber Number in fluid mechanics?
A. Ratio of inertial forces to gravitational forces
, B. Ratio of pressure forces to viscous forces
C. Ratio of inertial forces to surface tension forces
D. Ratio of buoyancy forces to surface tension
Answer: C
Conceptual Explanation: The Weber number is a dimensionless number that
characterizes the importance of surface tension relative to inertia, crucial for droplet and
bubble analysis.
5. Under what condition is the stream function (ψ) defined for a flow field?
A. The flow must be irrotational.
B. The flow must be steady.
C. The flow must satisfy the continuity equation.
D. The flow must be inviscid.
Answer: C
Conceptual Explanation: The stream function is mathematically defined such that it
automatically satisfies the continuity equation for 2D incompressible flows.
6. What happens to the stagnation pressure across a normal shock wave in a compressible
flow?
A. It increases.
B. It remains constant.
