Statistical Description of Intermittency in the Transition Region at the Low Degree of Flow Turbulence

摘要: The statistical method for describing the intermittency coefficient in region of laminar–turbulent boundary layer transition at low level external perturbations is proposed. based on assumption that turbulence develops when velocity deviates locally space and time from mean by a threshold value. analytical formulas are obtained frequency occurrence coherent structures (turbulent spots wedges) or fraction surface area covered them case two basic scenarios transition, namely, enhancement steady crossflow instability vortices swept wing Tollmien–Schlichting waves.