The region next to an obstacle in which all changes to the flow pattern occur. Outside the boundary layer, the flow is independent of the Reynolds number. The thickness of the boundary layer can be found by finding the distance over which inertia and viscous forces are comparable. Define as the distance scale of viscous forces
giving
Blasius Profile, Boundary Layer Separation, Drag Coefficient, Drag Force, Leidenfrost Effect, Spin-Down Time, Thermal Boundary Layer
