BME Fluid Mechanics 3

Question 1

The Moody diagram relates the Darcy friction factor to:

Accepted Answer

Reynolds number and relative pipe roughness

Answer

The Moody diagram provides friction factor f as a function of Reynolds number Re and relative roughness ε/D.

Question 2

For an ideal (inviscid, incompressible) fluid, Bernoulli's equation assumes which condition along a streamline?

Accepted Answer

Steady, incompressible, inviscid flow with no shaft work

Answer

Bernoulli's equation applies along a streamline for steady, incompressible, inviscid flow with no external work done.

Question 3

Which non-dimensional parameter characterizes the ratio of buoyancy forces to viscous forces in natural convection flows?

Accepted Answer

Grashof number

Answer

The Grashof number (Gr = gβΔTL³/ν²) represents buoyancy to viscous force ratio in natural convection.

Question 4

A hydraulic jump occurs in open channel flow when the flow transitions from:

Accepted Answer

Supercritical to subcritical

Answer

A hydraulic jump is an abrupt transition from supercritical (Fr > 1) to subcritical (Fr < 1) flow with significant energy loss.

Question 5

The stream function ψ is defined such that lines of constant ψ represent:

Accepted Answer

Streamlines of the flow

Answer

The stream function ψ is defined so that ∂ψ/∂y = u and ∂ψ/∂x = −v, making iso-ψ lines identical to streamlines.

BME - Bachelor of Mechanical Engineering Practice Test