Answer to Question #48201 in Engineering for Agam

Question

What is a boundary layer?

Answer 1

Answer
Boundary layer is thin layer of a flowing gas or liquid in contact with a surfacesuch as that of an airplane wing or of the inside of a pipe. The fluid in the
boundary layer is subjected to shearing forces. A range of velocities exists
across the boundary layer from maximum to zero, provided the fluid is in
contact with the surface. Boundary layers are thinner at the leading edge of an
aircraft wing and thicker toward the trailing edge. The flow in such boundary
layers is generally laminar at the leading or upstream portion and turbulent in
the trailing or downstream portion.