In flight mechanics, the “boundary layer” is a thin layer of air that forms near the surface of an aircraft’s wing or other aerodynamic surfaces as it moves through the air. This layer of air experiences a gradual transition from the free-stream airflow (far away from the surface) to a velocity of zero at the surface itself. The boundary layer plays a crucial role in the aerodynamics of the aircraft.
Rx=Uex/v
- Rx: Reynolds number. It is a dimensionless value and does not have any units.
- Uex: external velocity
- v: Kinematic viscosity of the fluid.