Which scientist introduced the concept of the boundary layer in fluid mechanics?

Ludwig Prandtl

The boundary layer thickness is denoted by which symbol?

Δ

True or False: The velocity gradient du/dy is negligible outside the boundary layer.

True

Riddle: I am a thin layer where friction dominates, yet I separate flow from inviscid regions. What am I?

Boundary layer

Fill-in-the-blank: The maximum velocity of the fluid in the free stream is represented as ______.

U∞

What happens to the fluid velocity at the wall under the no-slip condition?

It becomes zero.

Which equation is simplified into Prandtl's boundary-layer equations?

Navier-Stokes equations

In the context of boundary layers, what is the significance of the Reynolds number?

It indicates the flow regime, determining whether the flow is laminar or turbulent.

True or False: Momentum thickness is defined as the distance by which the boundary should be displaced to compensate for the reduction in velocity.

False. Momentum thickness compensates for the reduction in momentum, not just velocity.

What is the primary characteristic of turbulent flow compared to laminar flow?

Turbulent flow exhibits random particle motion, while laminar flow consists of smooth, orderly layers.