Prandtl boundary layer equations

Summary

The Prandtl boundary layer equations describe the thin layer near a wall where a fluid of small viscosity is slowed down by the no-slip condition. Ludwig Prandtl derived them in 1904 from the Navier–Stokes equations by a scaling argument in the thin layer. They connect the inviscid outer flow, governed by the Euler equations, to the wall. They are the foundation of boundary layer theory and of matched asymptotics.