Spanwise propagation of turbulence in the plane Couette flow

Propagation of turbulence in the plane Couette flow is analysed based on the Nee-Kovasznay model. The flow state is assumed uniform in the main stream direction, and a turbulent region is assumed to propagate spanwise into the laminar region with a constant speed. The speed is obtained to be 0.08U₀, where the velocity difference between two boundaries is 2U₀. Possible applications of this result are discussed.