undercut by a thin channel of irrotational flow. Here, a simple analysis is able to reproduce many of the complex features of turbulent mixing (J. Fluid Mech.485: 143-159 (2003).

As they mix, momentum differences are smoothed out. This process is superficially similar to the action of viscosity which tends to smooth out momentum gradients by molecular interactions, and ...

because turbulence is a very effective mixing process. More importantly, turbulent transport of momentum is very effective at replenishing the near-wall momentum. So when a turbulent boundary layer ...